sign in sign up
<<
Home , Geometry, Mathematics

Ohio’s Learning Standards DRAFT 2018 GEOMETRY COURSE STANDARDS | DRAFT 2018 2

Table of Contents

Table of Contents ...... 2 Introduction ...... 3 STANDARDS FOR MATHEMATICAL PRACTICE ...... 4 Mathematical Content Standards for High School ...... 7 How to Read the High School Content Standards ...... 8 GEOMETRY CRITICAL OF FOCUS ...... 10 GEOMETRY COURSE OVERVIEW ...... 12 High School—Modeling ...... 13 High School—Geometry ...... 15 Geometry Standards ...... 17 High School— and Probablity ...... 21 Statistics and Standards ...... 22 Glossary ...... 23 Table 3. The Properties of Operations...... 27 Table 4. The Properties of ...... 27 Table 5. The Properties of ...... 28 Acknowledgements ...... 29

GEOMETRY COURSE STANDARDS | DRAFT 2018 3

(a + b + c)( + y). Mathematical and procedural skill Introduction are equally important, and both are assessable using mathematical PROCESS tasks of sufficient richness. To better prepare students for college and careers, educators used public comments along with their professional expertise and The standards are grade-specific. However, they do not define the experience to revise Ohio’s Learning Standards. In spring 2016, the intervention methods or materials necessary to students who public gave feedback on the standards through an online survey. are well below or well above grade-level expectations. It is also Advisory committee members, representing various Ohio beyond the scope of the standards to define the full range of supports associations, reviewed all survey feedback and identified needed appropriate for English learners and for students with special needs. changes to the standards. Then they sent their directives to working At the same , all students must have the opportunity to learn and groups of educators who proposed the actual revisions to the meet the same high standards if they are to access the standards. The Ohio Department of Education sent their revisions and skills necessary in their post-school . Educators should read back out for public comment in July 2016. Once again, the Advisory the standards allowing for the widest possible range of students to Committee reviewed the public comments and directed the Working participate fully from the outset. They should provide appropriate to make further revisions. Upon finishing their work, the accommodations to ensure maximum participation of students with department presented the revisions to the Senate and House special education needs. For example, schools should allow students education committees as well as the Board of Education. with disabilities in reading to use Braille, screen reader or other assistive devices. Those with disabilities in writing should have UNDERSTANDING MATHEMATICS scribes, computers, or speech-to-text technology. In a similar vein, These standards define what students should understand and be able educators should interpret the speaking and listening standards to do in their study of mathematics. Asking a student to understand broadly to include language. No of grade-specific standards something asking a teacher to assess whether the student has can fully reflect the great variety in abilities, needs, learning rates, and understood it. But what does mathematical understanding look like? achievement levels of students in any given classroom. However, the One hallmark of mathematical understanding is the ability to justify, in standards do provide clear signposts along the way to help all a way appropriate to the student’s mathematical maturity, why a students achieve the goal of college and career readiness. particular mathematical statement is true, or where a mathematical rule comes from. There is a world of difference between a student The standards begin on page 4 with eight Standards for who can summon a mnemonic device to expand a such as Mathematical Practice. (a + b)(x + y) and a student who can explain where the mnemonic device comes from. The student who can explain the rule understands . the mathematics at a much deeper level. Then the student may have a better chance to succeed at a less familiar task such as expanding

GEOMETRY COURSE STANDARDS | DRAFT 2018 4

2. abstractly and quantitatively. Standards for Mathematical Practice Mathematically proficient students make sense of and their relationships in problem situations. They bring two complementary abilities to The Standards for Mathematical Practice describe varieties of expertise that bear on problems involving quantitative relationships: the ability to mathematics educators at all levels should seek to develop in their students. decontextualize—to abstract a given situation and represent it symbolically These practices rest on important “processes and proficiencies” with and manipulate the representing symbols as if they have a of their own, longstanding importance in . The first of these are the without necessarily attending to their referents—and the ability to NCTM process standards of , reasoning and , contextualize, to pause as needed during the manipulation process in to communication, representation, and connections. The second are the strands probe into the referents for the symbols involved. Quantitative reasoning of mathematical proficiency specified in the National Council’s report entails habits of creating a coherent representation of the problem at hand; Adding It Up: adaptive reasoning, strategic competence, conceptual considering the units involved; attending to the meaning of quantities, not just understanding (comprehension of mathematical , operations and how to compute them; and knowing and flexibly using different properties of relations), procedural fluency (skill in carrying out procedures flexibly, operations and objects. accurately, efficiently, and appropriately), and productive disposition (habitual inclination to see mathematics as sensible, useful, and worthwhile, coupled with a belief in diligence and one’s own efficacy). 3. Construct viable arguments and critique the reasoning of others. Mathematically proficient students understand and use stated assumptions, , and previously established in constructing arguments. They 1. Make sense of problems and persevere in solving them. make and build a logical progression of statements to explore the Mathematically proficient students start by explaining to themselves the of their conjectures. They are able to analyze situations by breaking them meaning of a problem and looking for entry points to its solution. They analyze into cases, and can recognize and use . They justify their givens, constraints, relationships, and goals. They make conjectures about the conclusions, communicate them to others, and respond to the arguments of form and meaning of the solution and plan a solution pathway rather than others. They reason inductively about , making plausible arguments that simply jumping into a solution attempt. They consider analogous problems, take into account the context from which the data arose. Mathematically and try special cases and simpler forms of the original problem in order to gain proficient students are also able to compare the effectiveness of two plausible insight into its solution. They monitor and evaluate their progress and change arguments, distinguish correct or reasoning from that which is flawed, course if necessary. Older students might, depending on the context of the and—if there is a flaw in an argument—explain what it is. Elementary students problem, transform algebraic expressions or change the viewing window on can construct arguments using concrete referents such as objects, drawings, their graphing to get the information they need. Mathematically diagrams, and actions. Such arguments can make sense and be correct, even proficient students can explain correspondences between , verbal though they are not generalized or made formal until later grades. Later, descriptions, tables, and graphs or draw diagrams of important features and students learn to determine domains to which an argument applies. Students relationships, graph data, and search for regularity or trends. Younger at all grades can listen or read the arguments of others, decide whether they students might rely on using concrete objects or pictures to help conceptualize make sense, and ask useful questions to clarify or improve the arguments. and solve a problem. Mathematically proficient students check their answers to problems using a different method, and they continually ask themselves, “Does this make sense?” They can understand the approaches of others to solving more complicated problems and identify correspondences between different approaches.

GEOMETRY COURSE STANDARDS | DRAFT 2018 5

Standards for Mathematical Practice, continued compare predictions with data. Mathematically proficient students at various grade levels are able to identify relevant external mathematical resources, 4. Model with mathematics. such as digital content located on a website, and use them to pose or solve Mathematically proficient students can the mathematics they know to problems. They are able to use technological tools to explore and deepen their solve problems arising in everyday life, society, and the workplace. In early understanding of concepts. grades, this might be as simple as writing an to describe a situation. In middle grades, a student might apply proportional reasoning to 6. Attend to precision. plan a school event or analyze a problem in the community. Mathematically proficient students try to communicate precisely to others. They try to use clear definitions in discussion with others and in their own By high school, a student might use geometry to solve a design problem or reasoning. They state the meaning of the symbols they choose, including use a to describe how one of interest depends on another. using the equal sign consistently and appropriately. They are careful about Mathematically proficient students who can apply what they know are specifying units of and labeling axes to clarify the correspondence comfortable making assumptions and to simplify a with quantities in a problem. They calculate accurately and efficiently and complicated situation, realizing that these may need revision later. express numerical answers with a of precision appropriate for the problem context. In the elementary grades, students give carefully formulated They are able to identify important quantities in a practical situation and explanations to each other. By the time they reach high school they have their relationships using such tools as diagrams, two-way tables, graphs, learned to examine claims and make explicit use of definitions. flowcharts, and . They can analyze those relationships mathematically to draw conclusions. They routinely interpret their 7. Look for and make use of structure. mathematical results in the context of the situation and reflect on whether Mathematically proficient students look closely to discern a or the results make sense, possibly improving the model if it has not served structure. Young students, for example, might notice that three and seven its purpose. more is the same amount as seven and three more, or they may sort a collection of according to how many sides the shapes have. Later, students will see 7 × 8 equals the well remembered 7 × 5 + 7 × 3, in preparation 5. Use appropriate tools strategically. 2 Mathematically proficient students consider the available tools when solving a for learning about the . In the x + 9x + 14, . These tools might include pencil and paper, concrete older students can see the 14 as 2 × 7 and the 9 as 2 + 7. They recognize the models, a ruler, a protractor, a calculator, a spreadsheet, a computer significance of an existing in a geometric figure and can use the strategy , a statistical package, or dynamic geometry software. Proficient of drawing an auxiliary line for solving problems. They also can step back for students are sufficiently familiar with tools appropriate for their grade or course an overview and shift . They can see complex things, such as some to make sound decisions about when each of these tools might be helpful, algebraic expressions, as single objects or as being composed of several 2 recognizing both the insight to be gained and their limitations. For example, objects. For example, they can see 5 – 3(x – y) as 5 minus a positive mathematically proficient high school students analyze graphs of functions and a and use that to realize that its value cannot be more than 5 for solutions generated using a graphing calculator. They detect possible errors any real x and y. by strategically using estimation and other mathematical knowledge. When making mathematical models, they know that technology can enable them to visualize the results of varying assumptions, explore consequences, and

GEOMETRY COURSE STANDARDS | DRAFT 2018 6

Standards for Mathematical Practice, continued content in mathematics instruction expertise throughout the elementary, middle, and high school years. Designers of curricula, assessments, and 8. Look for and express regularity in repeated reasoning. professional development should all attend to the need to connect the Mathematically proficient students notice if are repeated, and look mathematical practices to mathematical content in mathematics instruction. both for general methods and for shortcuts. Upper elementary students might notice when dividing 25 by 11 that they are repeating the same calculations The Standards for Mathematical Content are a balanced of over and over again, and conclude they have a repeating decimal. By paying procedure and understanding. Expectations that begin with the word attention to the of slope as they repeatedly check whether points “understand” are often especially good opportunities to connect the practices are on the line through (1, 2) with slope 3, students might abstract the equation to the content. Students who lack understanding of a topic may rely on (y − 2) /(x − 1) = 3. Noticing the regularity in the way terms cancel when expanding procedures too heavily. Without a flexible from which to work, they may (x − 1)(x + 1), (x − 1)(x2 + x + 1), and (x − 1)(x3 + x2 + x + 1) might lead them be less likely to consider analogous problems, represent problems coherently, to the general for the sum of a geometric . As they work to solve justify conclusions, apply the mathematics to practical situations, use a problem, mathematically proficient students maintain oversight of the technology mindfully to work with the mathematics, explain the mathematics process, while attending to the details. They continually evaluate the accurately to other students, step back for an overview, or deviate from a reasonableness of their intermediate results known procedure to find a shortcut. In short, a lack of understanding effectively prevents a student from engaging in the mathematical practices. In this respect, those content standards which set an expectation of understanding CONNECTING THE STANDARDS FOR MATHEMATICAL PRACTICE TO are potential “points of ” between the Standards for Mathematical THE STANDARDS FOR MATHEMATICAL CONTENT Content and the Standards for Mathematical Practice. These points of The Standards for Mathematical Practice describe ways in which developing intersection are intended to be weighted toward central and generative student practitioners of the discipline of mathematics increasingly ought to concepts in the school mathematics curriculum that most merit the time, engage with the subject as they grow in mathematical maturity and resources, innovative , and focus necessary to qualitatively improve expertise throughout the elementary, middle, and high school years. the curriculum, instruction, assessment, professional development, and Designers of curricula, assessments, and professional development should all student achievement in mathematics. attend to the need to connect the mathematical practices to mathematical

GEOMETRY COURSE STANDARDS | DRAFT 2018 7

Mathematical Content Standards for High School

PROCESS Modeling is best interpreted not as a collection of isolated topics but in The high school standards specify the mathematics that all students to other standards. Making mathematical models is a should study in order to be college and career ready. Additional Standard for Mathematical Practice, and specific modeling standards mathematics that students should learn in order to take advanced appear throughout the high school standards indicated by a courses such as , advanced statistics, or discrete ( ). mathematics is indicated by (+), as in this example: ★

(+) Represent complex numbers on the complex in Proofs in high school mathematics should not be limited to geometry. rectangular and polar form (including real and imaginary Mathematically proficient high school students employ multiple proof numbers). methods, including algebraic derivations, proofs using coordinates, and proofs based on geometric transformations, including All standards without a (+) symbol should be in the common . These proofs are supported by the use of diagrams and mathematics curriculum for all college and career ready students. dynamic software and are written in multiple formats including not just Standards with a (+) symbol may also appear in courses intended for two-column proofs but also proofs in paragraph form, including all students. However, standards with a (+) symbol will not appear on mathematical symbols. In statistics, rather than using mathematical Ohio’s State Tests. proofs, arguments are made based on within a properly designed statistical investigation. The high school standards are listed in conceptual categories: • Modeling • Number and Quantity • Algebra • Functions • Geometry • Statistics and Probability

Conceptual categories portray a coherent view of high school mathematics; a student’s work with functions, for example, crosses a number of traditional course boundaries, potentially up through and including calculus.

GEOMETRY COURSE STANDARDS | DRAFT 2018 8

Looking at the course designations, an Algebra 1 teacher should be How to Read the High School Content focusing his or her instruction on a. which focuses on linear functions; Standards b. which focuses on quadratic functions; and e. which focuses on simple exponential functions. An Algebra 1 teacher can ignore c., d., Conceptual Categories are that cross through and f, as the focuses of these types of functions will come in later various course boundaries. courses. However, a teacher may choose to touch on these types of functions to extend a topic if he or she wishes. Standards define what students should understand and be able to do.

Clusters are groups of related standards. Note that standards from different clusters may sometimes be closely related, because mathematics is a connected subject.

Domains are larger groups of related standards. Standards from different domains may sometimes be closely related.

G shows there is a in the glossary for this term.

(★) indicates that modeling should be incorporated into the standard. (See the Conceptual of Modeling pages 13-14)

(+) indicates that it is a standard for students who are planning on taking advanced courses. Standards with a (+) sign will not appear on Ohio’s State Tests.

Some standards have course designations such as (A1, M1) or (A2, M3) listed after an a., b., or c. .These designations help teachers know where to focus their instruction within the standard. In the example below the beginning of the standard is the stem. The stem shows what the teacher should be doing for all courses. (Notice in the example below that modeling (★) should also be incorporated.)

GEOMETRY COURSE STANDARDS | DRAFT 2018 9

How to Read the High School Content Standards, continued

Notice that in the standard below, the stem has a course designation. This shows that the full extent of the stem is intended for an Algebra 2 or Math 3 course. However, a. shows that Algebra 1 and Math 2 students are responsible for a modified version of the stem that focuses on transformations of quadratics functions and excludes the f(kx) transformation. However, again a teacher may choose to touch on different types of functions besides quadratics to extend a topic if he or she wishes.

GEOMETRY COURSE STANDARDS | DRAFT 2018 10

Geometry Critical Areas of Focus CRITICAL OF FOCUS #3 CRITICAL AREA OF FOCUS #1 , Proof, and Applications of Probability Students apply their earlier experience with dilations and proportional on probability concepts that began in grade 7, students use reasoning to build a formal understanding of similarity. They identify the languages of set to expand their ability to compute and criteria for similarity of , use it as a familiar foundation for the interpret theoretical and experimental for compound development of informal and formal proofs, problem solving and events, attending to mutually exclusive events, independent events, applications to similarity in right triangles. This will assist in the further and conditional probability. Students should make use of geometric development of right trigonometry, with particular attention to probability models wherever possible. They use probability to make special right triangles, right triangles with one side and one acute informed decisions related to real-world situations. given and the Pythagorean . Students apply geometric concepts to solve real-world, design and modeling problems. CRITICAL AREA OF FOCUS #2 , Proof and CRITICAL AREA OF FOCUS #4 In previous grades, students were asked to draw triangles based on Connecting Algebra and Geometry Through Coordinates given . They also have prior experience with rigid Building on their work with the in 8th grade to find : translations, reflections, and rotations and have used these to , students use a rectangular to verify develop notions about what it means for two objects to be congruent or geometric relationships, including properties of special triangles and to have symmetries of itself, rotational or reflected. Students establish and slopes of and lines. triangle congruence criteria, based on analyses of rigid motions and formal . They use triangle congruence as a familiar CRITICAL AREA OF FOCUS #5 foundation for the development of formal and informal proof. Students With and Without Coordinates prove —using a variety of formats—and apply them when Students prove basic theorems about circles, such as a line is solving problems about triangles, quadrilaterals, and other . perpendicular to a , theorem, and theorems about They apply reasoning to complete geometric constructions and explain chords, secants, and dealing with segment and angle why they work. Students will extend prior experience with geometric measures. They study relationships among segments on chords, shapes toward the development of a of two-dimensional secants, and tangents as an application of similarity. Students use the figures based on formal properties. formula to write the equation of a when given the radius and the coordinates of its center. Given an equation of a circle, they draw the graph in the coordinate plane, and apply techniques for

solving quadratic equations, which relates back to work done with

of equations in the first course to determine between lines and circles. Students model and solve real-world problems applying these geometric concepts.

GEOMETRY COURSE STANDARDS | DRAFT 2018 11

Geometry Critical Areas of Focus, continued

CRITICAL AREA OF FOCUS #6 Extending to Three Students’ experience with two-dimensional and three dimensional objects is extended to include informal explanations of , area and formulas. Students develop the understanding of how changes in dimensions in similar and non-similar shapes and how scaling changes lengths, areas and . Additionally, students apply their knowledge of two-dimensional shapes to consider the shapes of cross-sections and the result of rotating a two- dimensional object about a line. They solve real-world problems applying these geometric concepts.

GEOMETRY COURSE STANDARDS | DRAFT 2018 12

GEOMETRY COURSE OVERVIEW

MATHEMATICAL PRACTICES GEOMETRY 1. Make sense of problems and persevere in solving them. CONGRUENCE • Experiment with transformations in the plane. 2. Reason abstractly and quantitatively. • Understand congruence in terms of rigid motions. 3. Construct viable arguments and critique the reasoning • Prove geometric theorems both formally and informally using a of others. variety of methods. • Make geometric constructions. 4. Model with mathematics. • Classify and analyze geometric figures. 5. Use appropriate tools strategically. 6. Attend to precision. SIMILARITY, RIGHT TRIANGLES, AND TRIGONOMETRY 7. Look for and make use of structure. • Understand similarity in terms of similarity transformations. • Prove and apply theorems involving similarity both formally and 8. Look for and express regularity in repeated reasoning. informally using a variety of methods. • Define trigonometric , and solve problems involving right triangles. GEOMETRIC AND • Explain volume formulas, and use them to solve problems. CIRCLES • Visualize relationships between two- dimensional and three- • Understand and apply theorems about circles. dimensional objects. • Find arc lengths and areas of sectors of circles. • Understand the relationships between lengths, area, and volumes.

MODELING IN GEOMETRY • Apply geometric concepts in modeling situations. STATISTICS AND PROBABILITY CONDITIONAL PROBABILITY AND THE RULES EXPRESSING GEOMETRIC PROPERTIES WITH EQUATIONS OF PROBABILITY • Translate between the geometric description and the equation • Understand independence and conditional probability, and use for a . them to interpret data. • Use coordinates to prove simple geometric theorems • Use the rules of probability to compute probabilities of algebraically and to verify specific geometric statements. compound events in a uniform probability model.

GEOMETRY COURSE STANDARDS | DRAFT 2018 13

Some examples of such situations might include the following: High School—Modeling • Estimating how much water and food is needed for emergency Modeling links classroom mathematics and statistics to everyday life, relief in a devastated city of 3 million people, and how it might work, and decision-making. Modeling is the process of choosing and be distributed. using appropriate mathematics and statistics to analyze empirical • Planning a table tennis tournament for 7 players at a club with 4 situations, to understand them better, and to improve decisions. tables, where each player plays against each other player. Quantities and their relationships in physical, economic, public policy, • Designing the layout of the stalls in a school fair so as to raise as social, and everyday situations can be modeled using mathematical much money as possible. and statistical methods. When making mathematical models, • Analyzing stopping distance for a car. technology is valuable for varying assumptions, exploring • Modeling savings account balance, bacterial colony growth, or consequences, and comparing predictions with data. investment growth. • Engaging in critical , e.g., applied to turnaround of an aircraft at an airport. A model can be very simple, such as writing total cost as a product of • Analyzing in situations such as extreme sports, pandemics, unit price and number bought, or using a geometric to describe and terrorism. a like a coin. Even such simple models involve making • Relating population statistics to individual predictions. choices. It is up to us whether to model a coin as a three-dimensional , or whether a two-dimensional works well enough for our In situations like these, the models devised depend on a number of purposes. Other situations—modeling a delivery route, a production factors: How precise an answer do we want or need? What aspects of schedule, or a comparison of loan amortizations—need more the situation do we most need to understand, control, or optimize? elaborate models that use other tools from the mathematical . What resources of time and tools do we have? The range of models Real-world situations are not organized and labeled for analysis; that we can create and analyze is also constrained by the limitations formulating tractable models, representing such models, and of our mathematical, statistical, and technical skills, and our ability to analyzing them is appropriately a creative process. Like every such recognize significant variables and relationships among them. process, this depends on acquired expertise as well as . Diagrams of various kinds, spreadsheets and other technology, and algebra are powerful tools for understanding and solving problems drawn from different types of real-world situations.

GEOMETRY COURSE STANDARDS | DRAFT 2018 14

High School—Modeling, continued In descriptive modeling, a model simply describes the phenomena or summarizes them in a compact form. Graphs of observations are a One of the insights provided by mathematical modeling is that familiar descriptive model—for example, graphs of global temperature essentially the same mathematical or statistical structure can and atmospheric CO2 over time. sometimes model seemingly different situations. Models can also shed light on the mathematical structures themselves, for example, as Analytic modeling seeks to explain data on the of deeper when a model of bacterial growth makes more vivid the explosive theoretical ideas, albeit with that are empirically based; growth of the . for example, exponential growth of bacterial colonies (until cut-off mechanisms such as pollution or starvation intervene) follows from a The basic modeling cycle is summarized in the diagram. It involves (1) reproduction rate. Functions are an important tool for identifying variables in the situation and selecting those that represent analyzing such problems. essential features, (2) formulating a model by creating and selecting geometric, graphical, tabular, algebraic, or statistical representations Graphing utilities, spreadsheets, systems, and that describe relationships between the variables, (3) analyzing and dynamic geometry software are powerful tools that can be used to performing operations on these relationships to draw conclusions, (4) model purely mathematical phenomena, e.g., the behavior of interpreting the results of the mathematics in terms of the original as well as physical phenomena. situation, (5) validating the conclusions by comparing them with the situation, and then either improving the model or, if it is acceptable, (6) reporting on the conclusions and the reasoning behind them. MODELING STANDARDS Choices, assumptions, and approximations are present throughout Modeling is best interpreted not as a collection of isolated topics but this cycle. rather in relation to other standards. Making mathematical models is a Standard for Mathematical Practice, and specific modeling standards appear throughout the high school standards indicated by a star symbol (★). PROBLEM FORMULATE VALIDATE REPORT

COMPUTE INTERPRET

GEOMETRY COURSE STANDARDS | DRAFT 2018 15

High School—Geometry In the approach taken here, two geometric figures are defined to be An understanding of the attributes and relationships of geometric congruent if there is a of rigid motions that carries one onto objects can be applied in diverse contexts—interpreting a schematic the other. This is the principle of superposition. For triangles, drawing, estimating the amount of wood needed to frame a sloping congruence means the equality of all corresponding pairs of sides and roof, rendering computer , or designing a sewing pattern for all corresponding pairs of . During the middle grades, through the most efficient use of material. experiences drawing triangles from given conditions, students notice ways to specify enough measures in a triangle to ensure that all Although there are many types of geometry, school mathematics is triangles drawn with those measures are congruent. Once these devoted primarily to plane , studied both triangle congruence criteria (ASA, SAS, and SSS) are established synthetically (without coordinates) and analytically (with coordinates). using rigid motions, they can be used to prove theorems about Euclidean geometry is characterized most importantly by the Parallel triangles, quadrilaterals, and other geometric figures. Postulate, that through a not on a given line there is exactly one parallel line. (, in contrast, has no parallel lines.) Similarity transformations (rigid motions followed by dilations) define similarity in the same way that rigid motions define congruence, During high school, students begin to formalize their geometry thereby formalizing the similarity ideas of “same shape” and “scale experiences from elementary and , using more precise factor” developed in the middle grades. These transformations lead to definitions and developing careful proofs. Later in college some the criterion for triangle similarity that two pairs of corresponding students develop Euclidean and other carefully from a angles are congruent. small set of . The definitions of , cosine, and tangent for acute angles are The concepts of congruence, similarity, and can be founded on right triangles and similarity, and, with the Pythagorean understood from the perspective of . Theorem, are fundamental in many real-world and theoretical Fundamental are the rigid motions: translations, rotations, reflections, situations. The Pythagorean Theorem is generalized to non- right and of these, all of which are here assumed to preserve triangles by the . Together, the Laws of and distance and angles (and therefore shapes generally). Reflections and Cosines embody the triangle congruence criteria for the cases where rotations each explain a particular type of symmetry, and the three pieces of information suffice to completely solve a triangle. symmetries of an object offer insight into its attributes— as when the Furthermore, these laws yield two possible solutions in the ambiguous reflective symmetry of an assures that its base case, illustrating that Side-Side-Angle is not a congruence criterion. angles are congruent.

GEOMETRY COURSE STANDARDS | DRAFT 2018 16

High School—Geometry, continued

Analytic geometry connects algebra and geometry, resulting in powerful methods of analysis and problem solving. Just as the number line associates numbers with locations in one dimension, a pair of perpendicular axes associates pairs of numbers with locations in two dimensions. This correspondence between numerical coordinates and geometric points allows methods from algebra to be applied to geometry and vice versa. The of an equation becomes a geometric , making a tool for doing and understanding algebra. Geometric shapes can be described by equations, making algebraic manipulation into a tool for geometric understanding, modeling, and proof. Geometric transformations of the graphs of equations correspond to algebraic changes in their equations.

Dynamic geometry environments provide students with experimental and modeling tools that allow them to investigate geometric phenomena in much the same way as computer algebra systems allow them to experiment with algebraic phenomena.

CONNECTIONS TO EQUATIONS The correspondence between numerical coordinates and geometric points allows methods from algebra to be applied to geometry and vice versa. The solution set of an equation becomes a geometric curve, making visualization a tool for doing and understanding algebra. Geometric shapes can be described by equations, making algebraic manipulation into a tool for geometric understanding, modeling, and proof.

GEOMETRY COURSE STANDARDS | DRAFT 2018 17

Understand congruence in terms of rigid motions. Geometry Standards G.CO.6 Use geometric descriptions of rigid motionsG to transform CONGRUENCE G.CO figures and to predict the effect of a given rigid on a given Experiment with transformations in the plane. figure; given two figures, use the definition of congruence in terms of G G.CO.1 Know precise definitions of ray, angle, circle, perpendicular rigid motions to decide if they are congruent . line, parallel line, and , based on the notions of G.CO.7 Use the definition of congruence in terms of rigid motions to point, line, distance along a line, and arc . show that two triangles are congruent corresponding G.CO.2 Represent transformations in the plane using, e.g., pairs of sides and corresponding pairs of angles are congruent. transparencies and geometry software; describe transformations as G.CO.8 Explain how the criteria for triangle congruence (ASA, functions that take points in the plane as inputs and give other points SAS, and SSS) follow from the definition of congruence in terms of as outputs. Compare transformations that preserve distance and rigid motions. angle to those that do not, e.g., versus horizontal stretch. G.CO.3 Identify the symmetries of a figure, which are the rotations Prove geometric theorems both formally and informally using a and reflections that carry it onto itself. variety of methods. a. Identify figures that have line symmetry; draw and use lines of G.CO.9 Prove and apply theorems about lines and angles. Theorems symmetry to analyze properties of shapes. include but are not restricted to the following: vertical angles are b. Identify figures that have rotational symmetry; determine the congruent; when a crosses parallel lines, alternate angle of , and use rotational symmetry to analyze angles are congruent and corresponding angles are congruent; points properties of shapes. on a perpendicular bisector of a line segment are exactly those G.CO.4 Develop definitions of rotations, reflections, and translations equidistant from the segment's endpoints. in terms of angles, circles, perpendicular lines, parallel lines, and G.CO.10 Prove and apply theorems about triangles. Theorems line segments. include but are not restricted to the following: measures of interior G.CO.5 Given a geometric figure and a rotation, reflection, or angles of a triangle sum to 180°; base angles of isosceles triangles translation, draw the transformed figure using items such as graph are congruent; the segment joining of two sides of a triangle paper, tracing paper, or geometry software. Specify a sequence of is parallel to the third side and half the length; the medians of a transformations that will carry a given figure onto another. triangle meet at a point. G.CO.11 Prove and apply theorems about . Theorems include but are not restricted to the following: opposite sides are congruent, opposite angles are congruent, the of a bisect each other, and conversely, are parallelograms with congruent diagonals.

GEOMETRY COURSE STANDARDS | DRAFT 2018 18

Geometry Standards, continued G.SRT.3 Use the properties of similarity transformations to establish the AA criterion for two triangles to be similar. CONGRUENCE, CONTINUED G.CO Make geometric constructions. Prove and apply theorems both formally and informally involving G.CO.12 Make formal geometric constructions with a variety of tools similarity using a variety of methods. and methods ( and straightedge, string, reflective devices, G.SRT.4 Prove and apply theorems about triangles. Theorems paper folding, dynamic geometric software, etc.). Copying a segment; include but are not restricted to the following: a line parallel to one copying an angle; bisecting a segment; bisecting an angle; side of a triangle divides the other two proportionally, and conversely; constructing perpendicular lines, including the perpendicular bisector the Pythagorean Theorem proved using triangle similarity. of a line segment; and constructing a line parallel to a given line G.SRT.5 Use congruence and similarity criteria for triangles to solve through a point not on the line. problems and to justify relationships in geometric figures that can be G.CO.13 Construct an , a square, and a regular decomposed into triangles. inscribed in a circle. Define trigonometric ratios, and solve problems involving Classify and analyze geometric figures. right triangles. G.CO.14 Classify two-dimensional figures in a hierarchy based G.SRT.6 Understand that by similarity, side ratios in right triangles are on properties. properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles. SIMILARITY, RIGHT TRIANGLES, AND TRIGONOMETRY G.SRT G.SRT.7 Explain and use the relationship between the sine and Understand similarity in terms of similarity transformations. cosine of complementary angles. G.SRT.1 Verify experimentally the properties of dilationsG given by a G.SRT.8 Solve problems involving right triangles.★ center and a scale factor: a. Use trigonometric ratios and the Pythagorean Theorem to solve a. A dilation takes a line not passing through the center of the right triangles in applied problems if one of the two acute angles dilation to a parallel line and leaves a line passing through the and a side length is given. (G, M2) center unchanged. b. The dilation of a line segment is longer or shorter in the given by the scale factor. G.SRT.2 Given two figures, use the definition of similarity in terms of similarity transformationsG to decide if they are similar; explain using similarity transformations the meaning of similarity for triangles as the equality of all corresponding pairs of angles and the proportionality of all corresponding pairs of sides.

GEOMETRY COURSE STANDARDS | DRAFT 2018 19

Geometry Standards, continued EXPRESSING GEOMETRIC PROPERTIES CIRCLES G.C WITH EQUATIONS G.GPE Understand and apply theorems about circles. Translate between the geometric description and the equation G.C.1 Prove that all circles are similar using transformational for a conic section. arguments. G.GPE.1 Derive the equation of a circle of given center and radius G.C.2 Identify and describe relationships among angles, radii, chords, using the Pythagorean Theorem; complete the square to find the tangents, and arcs and use them to solve problems. Include the center and radius of a circle given by an equation. relationship between central, inscribed, and circumscribed angles and their intercepted arcs; inscribed angles on a are right angles; Use coordinates to prove simple geometric theorems the radius of a circle is perpendicular to the tangent where the radius algebraically and to verify specific geometric statements. intersects the circle. G.GPE.4 Use coordinates to prove simple geometric theorems G.C.3 Construct the inscribed and circumscribed circles of a triangle; algebraically and to verify geometric relationships algebraically, prove and apply the property that opposite angles are supplementary including properties of special triangles, quadrilaterals, and circles. for a inscribed in a circle. For example, determine if a figure defined by four given points in the (+) G.C.4 Construct a tangent line from a point outside a given circle coordinate plane is a ; determine if a specific point lies on a to the circle. given circle. (G, M2) G.GPE.5 Justify the slope criteria for parallel and perpendicular lines, Find arc lengths and areas of sectors of circles. and use them to solve geometric problems, e.g., find the equation of a G.C.5 Find arc lengths and areas of sectors of circles. line parallel or perpendicular to a given line that passes through a a. Apply similarity to relate the length of an arc intercepted given point. by a central angle to the radius. Use the relationship to G.GPE.6 Find the point on a directed line segment between two given solve problems. (G, M2) points that partitions the segment in a given ratio. b. Derive the formula for the area of a , and use it to G.GPE.7 Use coordinates to compute perimeters of polygons and solve problems. (G, M2) areas of triangles and rectangles, e.g., using the distance formula.★

GEOMETRY COURSE STANDARDS | DRAFT 2018 20

Geometry Standards, continued

GEOMETRIC MEASUREMENT AND DIMENSION G.GMD MODELING WITH GEOMETRY G.MG Explain volume formulas, and use them to solve problems. Apply geometric concepts in modeling situations. G.GMD.1 Give an informal argument for the formulas for the G.MG.1 Use geometric shapes, their measures, and their properties circumference of a circle, , and volume of a cylinder, to describe objects, e.g., modeling a tree trunk or a torso as , and . Use dissection arguments, Cavalieri's principle, a cylinder. and informal arguments. ★ Apply concepts of density based on area and volume in G.GMD.3 Use volume formulas for , pyramids, , and G.MG.2 modeling situations, e.g., persons per square mile, BTUs per to solve problems. ★ cubic foot. ★ Apply geometric methods to solve design problems, e.g., Visualize relationships between two-dimensional and three- G.MG.3 designing an object or structure to satisfy physical constraints or dimensional objects. minimize cost; working with typographic grid systems based G.GMD.4 Identify the shapes of two-dimensional cross-sections of three-dimensional objects, and identify three-dimensional objects on ratios.★ generated by rotations of two-dimensional objects.

Understand the relationships between lengths, areas, and volumes. G.GMD.5 Understand how and when changes to the measures of a figure (lengths or angles) result in similar and non-similar figures. G.GMD.6 When figures are similar, understand and apply the fact that when a figure is scaled by a factor of k, the effect on lengths, areas, and volumes is that they are multiplied by k, k2, and k3, respectively.

GEOMETRY COURSE STANDARDS | DRAFT 2018 21

and other reports, it is important to consider the study design, how the High School—Statistics and Probablity data were gathered, and the analyses employed as well as the data summaries and the conclusions drawn. Decisions or predictions are often based on data—numbers in context. These decisions or predictions would be easy if the data Random processes can be described mathematically by using a always sent a clear message, but the message is often obscured by probability model: a list or description of the possible outcomes (the variability. Statistics provides tools for describing variability in data sample ), each of which is assigned a probability. In situations and for making informed decisions that take it into account. such as flipping a coin, rolling a number , or drawing a card, it might be reasonable to assume various outcomes are equally likely. Data are gathered, displayed, summarized, examined, and interpreted In a probability model, sample points represent outcomes and to discover and deviations from patterns. Quantitative data combine to make up events; probabilities of events can be computed can be described in terms of key characteristics: measures of shape, by applying the Addition and Rules. Interpreting these center, and spread. The shape of a data distribution might be probabilities relies on an understanding of independence and described as symmetric, skewed, , or bell shaped, and it might be conditional probability, which can be approached through the analysis summarized by a statistic measuring center (such as or of two-way tables. ) and a statistic measuring spread (such as standard deviation or interquartile range). Different distributions can be compared Technology plays an important role in statistics and probability by numerically using these statistics or compared visually using plots. making it possible to generate plots, regression functions, and Knowledge of center and spread are not enough to describe a correlation , and to simulate many possible outcomes in a distribution. Which statistics to compare, which plots to use, and what short amount of time. the results of a comparison might mean, depend on the question to be investigated and the real-life actions to be taken. CONNECTIONS TO FUNCTIONS AND MODELING Functions may be used to describe data; if the data suggest a linear Randomization has two important uses in drawing statistical relationship, the relationship can be modeled with a regression line, conclusions. First, collecting data from a random sample of a and its strength and direction can be expressed through a population makes it possible to draw valid conclusions about the correlation . whole population, taking variability into account. Second, randomly assigning individuals to different treatments allows a fair comparison of the effectiveness of those treatments. A statistically significant outcome is one that is unlikely to be due to chance alone, and this can be evaluated only under the condition of randomness. The conditions under which data are collected are important in drawing conclusions from the data; in critically reviewing uses of statistics in public media

GEOMETRY COURSE STANDARDS | DRAFT 2018 22

Statistics and Probability Standards CONDITIONAL PROBABILITY AND THE RULES OF PROBABILITY S.CP S.CP.5 Recognize and explain the concepts of conditional probability Understand independence and conditional probability, and use and independence in everyday language and everyday situations. For them to interpret data. example, compare the chance of having lung cancer if you are a S.CP.1 Describe events as of a sample space (the set of smoker with the chance of being a smoker if you have lung cancer.★ outcomes) using characteristics (or categories) of the outcomes, or as unions, intersections, or complements of other events (“or,” Use the rules of probability to compute probabilities of “and,” “not”).★ compound events in a uniform probability model. S.CP.2 Understand that two events A and B are independent if and S.CP.6 Find the conditional probability of A given B as the of only if the probability of A and B occurring together is the product of B’s outcomes that also belong to A, and interpret the answer in terms their probabilities, and use this characterization to determine if they of the model.★ are independent.★ S.CP.7 Apply the Addition Rule, P(A or B) = P(A) + P(B) − P(A and S.CP.3 Understand the conditional probability of A given B as B), and interpret the answer in terms of the model. P(A and B) ★ /P(B), and interpret independence of A and B as saying that the (+) S.CP.8 Apply the general Multiplication Rule in a uniform conditional probability of A given B is the same as the probability of A, probability modelG, P(A and B) = P(A)⋅P(B|A) = P(B)⋅P(A|B), and and the conditional probability of B given A is the same as the interpret the answer in terms of the model.★ (G, M2) probability of B.★ (+) S.CP.9 Use and combinations to compute S.CP.4 Construct and interpret two-way frequency tables of data probabilities of compound events and solve problems. (G, M2) when two categories are associated with each object being classified. ★

Use the two-way table as a sample space to decide if events are independent and to approximate conditional probabilities. For example, collect data from a random sample of students in your school on their favorite subject among math, , and English.

Estimate the probability that a randomly selected student from your school will favor science given that the student is in tenth grade. Do the same for other subjects and compare the results. ★

GEOMETRY COURSE STANDARDS | DRAFT 2018 23

______Glossary of Computation . A on. A strategy 1 Adapted from Wisconsin multiplication. See Table set of predefined steps for finding the number of Department of Public Instruction, 3 in this Glossary. applicable to a of objects in a group without http://dpi.wi.gov/ Addition and standards/mathglos.html, accessed within 5, 10, 20, 100, or problems that gives the having to count every March 2, 2010. 1000. Addition or Bivariate data. Pairs of correct result in every case member of the group. For 2 Many different methods for subtraction of two whole linked numerical when the steps are carried example, if a of computing quartiles are in use. The observations. Example: a out correctly. See also: books is known to have 8 method defined here is sometimes numbers with whole called the Moore and McCabe number answers, and with list of heights and weights computation strategy. books and 3 more books method. See Langford, E., “Quartiles sum or minuend in the for each player on a are added to the top, it is in Elementary Statistics,” Journal of not necessary to count the Volume 14, range 0-5, 0-10, 0-20, or football team. Computation strategy. Number 3 (2006). 0-100, respectively. Purposeful manipulations stack all over again. One can find the total by Example: 8 + 2 = 10 is an Box . A method of that may be chosen for counting on—pointing to addition within 10, 14 − 5 = visually displaying a specific problems, may not the top book and saying 9 is a subtraction within 20, distribution of data values have a fixed order, and “eight,” following this with and 55 − 18 = 37 is a by using the median, may be aimed at “nine, ten, eleven. There subtraction within 100. quartiles, and extremes of converting one problem are eleven books now.” the data set. A box shows into another. See also: Additive inverses. Two the middle 50% of the computation algorithm. numbers whose sum is 0 data.1 See also: first Dilation. A transformation are additive inverses of one quartile and third quartile. Congruent. Two plane or that moves each point another. Example: ¾ and solid figures are congruent along the ray through the 3 point emanating from a − /4 are additive inverses . if one can be obtained from fixed center, and multiplies of one another because ¾ See Table 3 in this the other by rigid motion (a 3 3 3 distances from the center + (− /4) = (− /4) + /4 = 0. Glossary. sequence of rotations, reflections, and by a common scale factor. translations). Algorithm. See also: Complex fraction. A A Dot plot. See also: line computation algorithm. fraction /B where A and/or plot. B are (B nonzero). Associative property of

addition. See Table 3 in this Glossary.

GEOMETRY COURSE STANDARDS | DRAFT 2018 24

______Expanded form. A multi- Fluently. See also: . A number Mean. A measure of center 3 Adapted from Wisconsin digit number is expressed fluency. expressible in the form a in a set of numerical data, Department of Public Instruction, op. in expanded form when it is or −a for some whole computed by adding the cit. written as a sum of single- Fraction. A number number a. values in a list and then 4 Adapted from Wisconsin digit multiples of powers of a dividing by the number of Department of Public Instruction, op. expressible in the form /b cit. ten. For example, where a is a whole number Interquartile Range. A values in the list. (To be 643 = 600 + 40 + 3. more precise, this defines and b is a positive whole measure of variation in a number. (The word fraction set of numerical data, the the mean) Expected value. For a in these standards always interquartile range is the Example: For the data set random , the refers to a non-negative distance between the first {1, 3, 6, 7, 10, 12, 14, 15, weighted average of its number.) See also: rational and third quartiles of the 22, 120}, the mean is 21. possible values, with number. data set. Example: For the weights given by their data set {1, 3, 6, 7, 10, 12, Mean absolute deviation. respective probabilities. property of 0. 14, 15, 22, 120}, the A measure of variation in a See Table 3 in this interquartile range is set of numerical data, First quartile. For a data Glossary. 15 − 6 = 9. See also: first computed by adding the set with median M, the first quartile, third quartile. distances between each data value and the mean, quartile is the median of Independently combined then dividing by the the data values less than probability models. Two Justify: To provide a number of data values. M. Example: For the data probability models are said convincing argument for Example: For the data set set {1, 3, 6, 7, 10, 12, 14, to be combined the truth of a statement to a {2, 3, 6, 7, 10, 12, 14, 15, 15, 22, 120}, the first independently if the particular audience. 22, 120}, the mean quartile is 6.2 See also: probability of each ordered absolute deviation is 20. median, third quartile, pair in the combined model Line plot. A method of interquartile range. equals the product of the visually displaying a original probabilities of the distribution of data values Fluency. The ability to use two individual outcomes in where each data value is efficient, accurate, and the . shown as a dot or mark flexible methods for above a number line. Also 3 computing. Fluency does known as a dot plot. not imply timed tests.

GEOMETRY COURSE STANDARDS | DRAFT 2018 25

Median. A measure of Multiplicative inverses. Probability distribution. Probability model. A center in a set of numerical Two numbers whose The set of possible values probability model is used to data. The median of a list product is 1 are of a random variable with a assign probabilities to of values is the value multiplicative inverses of probability assigned to outcomes of a chance 3 appearing at the center of a one another. Example: /4 each. process by examining the 4 sorted version of the list— and /3 are multiplicative of the process. The or the mean of the two inverses of one another Properties of operations. set of all outcomes is called

central values, if the list because See Table 3 in this the sample space, and 3 4 4 3 contains an even number /4 × /3 = /3 × /4 = 1. Glossary. their probabilities sum to 1. of values. Example: For the See also: uniform data set {2, 3, 6, 7, 10, 12, probability model. Number line diagram. A Properties of equality. 14, 15, 22, 90}, the median diagram of the number line See Table 4 in this is 11. used to represent numbers Glossary. Prove: To provide a and support reasoning logical argument that Midline. In the graph of a about them. In a number demonstrates the truth of Properties of inequality. trigonometric function, the line diagram for a statement. A proof is See Table 5 in this horizontal line halfway measurement quantities, typically composed of a Glossary. between its maximum and the from 0 to 1 on series of justifications, minimum values. the diagram represents which are often single the unit of measure for Properties of operations. sentences, and may be See Table 3 in this Multiplication and the quantity. presented informally Glossary. within 100. or formally. Multiplication or division of Percent rate of change. A two whole numbers with rate of change expressed Probability. A number Random variable. An between 0 and 1 used to whole number answers, as a percent. Example: if a assignment of a numerical and with product or population grows from 50 quantify likelihood for value to each outcome in a dividend in the range to 55 in a year, it grows by processes that have sample space.

5 uncertain outcomes (such 0-100. Example: /50 = 10% per year. as tossing a coin, selecting 72 ÷ 8 = 9. Rational expression. A a person at random from a quotient of two polynomials group of people, tossing a with a nonzero at a target, or testing denominator. for a medical condition).

GEOMETRY COURSE STANDARDS | DRAFT 2018 26

______Rational number. A Scatter plot. A graph in quartile is the median of Tests’ items will be written number expressible in the coordinate plane the data values greater so that either definition will 5 Adapted from Wisconsin a a Department of Public Instruction, op. the form /b or − /b for some representing a set of than M. Example: For the be acceptable. a cit. fraction /b. The rational bivariate data. For data set {2, 3, 6, 7, 10, 12, numbers include the example, the heights and 14, 15, 22, 120}, the third Uniform probability . weights of a group of quartile is 15. See also: model. A probability model people could be displayed median, first quartile, which assigns equal on a scatter plot.5 interquartile range. Rectilinear figure. A probability to all outcomes. all angles of which See also: probability are right angles. model. Similarity transformation. Transitivity principle for A rigid motion followed by indirect measurement. If A a dilation. the length of object A is A quantity with Rigid motion. Vector. transformation of points in greater than the length of and direction in space consisting of a Standard Algorithm. See object B, and the length of the plane or in space,

sequence of one or more Computational Algorithm object B is greater than the defined by an ordered pair translations, reflections, length of object C, then the or triple of real numbers. and/or rotations. Rigid length of object A is greater than the length of object C. motions are here assumed Tape diagram. A drawing Verify: To check the truth This principle applies to to preserve distances and that looks like a segment of or correctness of a measurement of other angle measures. tape, used to illustrate statement in specific cases. quantities as well. number relationships. Also Repeating decimal. The known as a strip diagram, Visual fraction model. A . 1. A trapezoid decimal form of a rational bar model, fraction strip, or tape diagram, number line is a quadrilateral with at number. See also: length model. diagram, or area model. terminating decimal. least one pair of parallel sides. (inclusive definition) Terminating decimal. A 2. A trapezoid is a Whole numbers. The Sample space. In a decimal is called quadrilateral with exactly numbers 0, 1, 2, 3, …. probability model for a terminating if its repeating one pair of parallel sides. random process, a list of digit is 0. (exclusive definition) the individual outcomes Districts may choose either that are to be considered. Third quartile. For a data definition to use for

set with median M, the third instruction. Ohio's State

GEOMETRY COURSE STANDARDS | DRAFT 2018 27

TABLE 3. THE PROPERTIES OF OPERATIONS. Here a, b and c stand for arbitrary numbers in a given number system. The properties of operations apply to the system, the system and the sytem. ASSOCIATIVE PROPERTY OF ADDITION ( + ) + = + ( + )

COMMUTATIVE PROPERTY OF ADDITION 𝑎𝑎+ 𝑏𝑏= 𝑐𝑐+ 𝑎𝑎 𝑏𝑏 𝑐𝑐 PROPERTY OF 0 𝑎𝑎 + 𝑏𝑏0 = 0𝑏𝑏 + 𝑎𝑎 = EXISTENCE OF ADDITIVE INVERSES 𝑎𝑎For ever there𝑎𝑎 𝑎𝑎exists so that + ( ) = ( ) + = 0 ASSOCIATIVE PROPERTY OF MULTIPLICATION ( × ) ×𝑎𝑎 = × ( × −) 𝑎𝑎 𝑎𝑎 −𝑎𝑎 −𝑎𝑎 𝑎𝑎 COMMUTATIVE PROPERTY OF MULTIPLICATION 𝑎𝑎× 𝑏𝑏= 𝑐𝑐× 𝑎𝑎 𝑏𝑏 𝑐𝑐 MULTIPLICATIVE IDENTITY PROPERTY OF 1 𝑎𝑎 × 𝑏𝑏1 = 1𝑏𝑏 × 𝑎𝑎 = EXISTENCE OF MULTIPLICATIVE INVERSES 𝑎𝑎For every 𝑎𝑎 0 𝑎𝑎there exists so that × = × = 1 1 1 1 DISTRIBUTIVE PROPERTY OF MULTIPLICATION OVER ADDITION × ( + )𝑎𝑎=≠ × + × 𝑎𝑎 𝑎𝑎 𝑎𝑎 𝑎𝑎 𝑎𝑎

𝑎𝑎 𝑏𝑏 𝑐𝑐 𝑎𝑎 𝑏𝑏 𝑎𝑎 𝑐𝑐

TABLE 4. THE PROPERTIES OF EQUALITY. Here a, b and c stand for arbitrary numbers in the rational, real or complex number sytems. REFLEXIVE PROPERTY OF EQUALITY =

SYMMETRIC PROPERTY OF EQUALITY 𝑎𝑎If =𝑎𝑎 , then = . TRANSITIVE PROPERTY OF EQUALITY If 𝑎𝑎 = 𝑏𝑏 and 𝑏𝑏= ,𝑎𝑎 then = . ADDITION PROPERTY OF EQUALITY If 𝑎𝑎 = 𝑏𝑏, then𝑏𝑏 +𝑐𝑐 = +𝑎𝑎 . 𝑐𝑐 SUBTRACTION PROPERTY OF EQUALITY If 𝑎𝑎 = 𝑏𝑏, then 𝑎𝑎 𝑐𝑐 = 𝑏𝑏 𝑐𝑐. MULTIPLICATION PROPERTY OF EQUALITY If 𝑎𝑎 = 𝑏𝑏, then 𝑎𝑎 −× 𝑐𝑐 = 𝑏𝑏 ×− 𝑐𝑐. DIVISION PROPERTY OF EQUALITY If 𝑎𝑎 = 𝑏𝑏 and 𝑎𝑎 0,𝑐𝑐 then𝑏𝑏 𝑐𝑐÷ = ÷ . SUBSTITUTION PROPERTY OF EQUALITY If 𝑎𝑎 = 𝑏𝑏, then𝑐𝑐 ≠ may be substituted𝑎𝑎 𝑐𝑐 𝑏𝑏 for𝑐𝑐 in any expression containing𝑎𝑎 𝑎𝑎 . 𝑏𝑏 𝑎𝑎

𝑎𝑎 GEOMETRY COURSE STANDARDS | DRAFT 2018 28

TABLE 5. THE PROPERTIES OF INEQUALITY. Here a, b and c stand for arbitrary numbers in the rational or real number sytems. Exactly one of the following is true: < , = , > .

If > and > , then𝑎𝑎 >𝑏𝑏 .𝑎𝑎 𝑏𝑏 𝑎𝑎 𝑏𝑏 𝑎𝑎 If𝑏𝑏 > 𝑏𝑏, then𝑐𝑐 < 𝑎𝑎. 𝑐𝑐 If 𝑎𝑎> ,𝑏𝑏 then 𝑏𝑏 < 𝑎𝑎 . If >𝑎𝑎 , 𝑏𝑏then ±−𝑎𝑎 > −𝑏𝑏± . If > 𝑎𝑎 and𝑏𝑏 > 0, 𝑎𝑎then𝑐𝑐 ×𝑏𝑏 >𝑐𝑐 × . If 𝑎𝑎 > 𝑏𝑏 and 𝑐𝑐 < 0, then 𝑎𝑎 × 𝑐𝑐 < 𝑏𝑏 × 𝑐𝑐. If 𝑎𝑎 > 𝑏𝑏 and 𝑐𝑐 > 0, then 𝑎𝑎 ÷ 𝑐𝑐 > 𝑏𝑏 ÷ 𝑐𝑐. If 𝑎𝑎 > 𝑏𝑏 and 𝑐𝑐 < 0, then 𝑎𝑎 ÷ 𝑐𝑐 < 𝑏𝑏 ÷ 𝑐𝑐.

𝑎𝑎 𝑏𝑏 𝑐𝑐 𝑎𝑎 𝑐𝑐 𝑏𝑏 𝑐𝑐

GEOMETRY COURSE STANDARDS | DRAFT 2018 29

Acknowledgements

ADVISORY COMMITTEE MEMBERS Aaron Altose Margie Coleman Courtney Koestler The Ohio Mathematics Association of Cochair Ohio Mathematics Education Two-Year Colleges Leadership Council Jason Feldner Ohio Association for Career and Jeremy Beardmore Scott Mitter Ohio Educational Service Center Association Technical Education Ohio Math and Science Supervisors

Jessica Burchett Brad Findell Tabatha Nadolny Ohio Teachers of English to Speakers of Ohio Ohio Federation of Teachers Other Languages Gregory D. Foley Eydie Schilling Ohio Mathematics and Science Coalition Ohio Association for Supervision and Jeanne Cerniglia Ohio Education Association Curriculum Development Margaret (Peggy) Kasten Cochair Kim Yoak Ohio Council of Teachers of Mathematics

GEOMETRY COURSE STANDARDS | DRAFT 2018 30

WORKING GROUP MEMBERS Darry Andrews Julie Kujawa Benjamin Shaw Higher Education, Ohio State , C Teacher, Oregon City, NW Curriculum Specialist/Coordinator, Mahoning County ESC, NE Bridgette Beeler Sharilyn Leonard Teacher, Perrysburg Exempted Local, NW Teacher, Oak Hill Union Local Schools, SE Julia Shew Higher Education, Columbus State Community Melissa Bennett Michael Lipnos College, C Teacher, Minford Local, SE Curriculum Specialist/Coordinator, Aurora City, NE Tiffany Sibert Dawn Bittner Teacher, Lima Shawnee Local, NW Teacher, Cincinnati Public Schools, SW Dawn Machacek Teacher, Toledo Public Schools, NW Jennifer Statzer Katherine Bunsey Principal, Greenville City, SW Teacher, Lakewood City, NE Janet McGuire Teacher, Gallia County Schools, SE Karma Vince Hoyun Cho Teacher, Sylvania City, NW Higher Education, Capital University, C Jill Madonia Curriculum Specialist/Coordinator, Jennifer Walls Viki Cooper Akron Public Schools, NE Teacher, Akron Public Schools, NE Curriculum Specialist/Coordinator, Pickerington Local, C Cindy McKinstry Gaynell Wamer Teacher, East Palestine City, NE Teacher, Toledo City, NW Ali Fleming Teacher, Bexley City, C Cindy Miller Victoria Warner Curriculum Specialist/Coordinator, Teacher, Greenville City, SW Linda Gillum Maysville Local, SE Teacher, Springboro City Schools, SW Mary Webb Anita O’Mellan Teacher, North College Hill, SW Gary Herman Higher Education, Youngstown State University, NE Curriculum Specialist/Coordinator, Barb Weidus Putnam County ESC, NW Sherryl Proctor Curriculum Specialist/Coordinator, Teacher, Vantage Career Center, NW New Richmond Exempted Village, SW William Husen Higher Education, Ohio State University, C Diane Reisdorff Sandra Wilder Teacher, Westlake City, NE Teacher, Akron Public Schools, NE Kristen Kelly Curriculum Specialist/Coordinator, Cleveland Susan Rice Tong Yu Metropolitan School District, NE Teacher, Mount Vernon City, C Teacher,Cincinnati Public Schools, SW

Endora Kight Neal Tess Rivero Curriculum Specialist/Coordinator, Cleveland Teacher, Bellbrook-Sugarcreek Schools, SW Metropolitan School District, NE