DOCSLIB.ORG

Geometry for Drafting Section 5.1 Applied Geometry for Board Drafting Section 5.2 Applied Geometry for CAD Systems

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geometry for Drafting Section 5.1 Applied Geometry for Board Drafting Section 5.2 Applied Geometry for CAD Systems 5 Geometry for Drafting Section 5.1 Applied Geometry for Board Drafting Section 5.2 Applied Geometry for CAD Systems Chapter Objectives • Identify geometric shapes and construc- tions used by drafters. • Construct various geometric shapes. • Solve technical and mathematical prob- lems through geomet- ric constructions using drafting instruments. • Solve technical and mathematical prob- lems through geomet- ric constructions using a CAD system. • Use geometry to reduce or enlarge a drawing or to change its proportions. Defying Convention It has been said that Zaha Hadid has built a career on defying convention—conventional ideas of architectural space, and of construction. What do you see in the building shown here that defi es convention? 132 Drafting Career Zaha Hadid, Architect Architect Zaha Hadid’s designs for the Cincinnati Contemporary Art Center were “like a rollercoaster, a little scary, but exhilarating,” says Center direc- tor Charles Desmarais. Critics said “she was a paper architect, someone who had great respect as a theo- rist and as a thinker about architecture but who hadn't had the opportunity to build.” “She totally got what we were trying to do,” said Desmarais, “which was to try and bridge that sort of gap between the inside and the outside, between the world and the museum.” She certainly did. Zaha Hadid is the fi rst woman in the world to design a museum and to win the prestigious Pritzker Architec- ture Prize. Academic Skills and Abilities • Math • Computer sciences • Business management skills • Verbal and written communication skills • Organizing and planning skills Career Pathways There is a wealth of opportunities outside the classroom for expanding your drafting knowledge. Learn about annual drafting contests. Even if you do not intend to apply, read about the projects. Find groups such as the Solar-Powered Car Chal- lenge; their ideas will inspire you. Go to glencoe.com for this book’s OLC to learn more about Zaha Hadid. 133 Zaha Hadid 5.1 Applied Geometry for Board Drafting Preview In this chapter, you will learn to construct geometric shapes using board drafting techniques. Have you learned geometric terms and formulas in other courses? Content Vocabulary • geometry • vertex • parallel • circumscribe • ellipse • geometric • bisect • polygon • regular construction • perpendicular • inscribe polygon Academic Vocabulary Learning these words while you read this section will also help you in your other subjects and tests. • accurate • methods Graphic Organizer Use a table like the one below to organize the major concepts about the types of geometric constructions. Bisect Construct Lines Construct Go to glencoe.com for this 1. Arc 1. Triangle 1. book’s OLC for a downloadable 2. 2. 2. version of this graphic organizer. 3. 3. 4. 5. 6. Academic Standards English Language Arts NCTE National Council of Teachers of English Students read a wide range of print and nonprint texts to build an understanding of texts (NCTE) NCTM National Council of Teachers of Mathematics Mathematics Students recognize and use connections among mathematical ideas (NCTM) 134 Chapter 5 Geometry for Drafting Geometry and Geometric Constructions 5 What do you need to be able to understand geometric constructions? B 4 C Geometry is the study of the size and ° 90 2 shape of objects, and of as the relationship 5 = 25 between straight and curved lines in draw- A 4 2 = 16 ing shapes. In ancient times, geometry A222 + B = C was used for measuring land and making 3 3222 + 4 = C accurate right-angle, or 90-degree, corners 9 + 16 = 25 for constructing buildings and other proj- 3 2 = 9 ects. When building the great pyramids, Ancient Egyptians formed right-angle cor- Figure 5-2 ners by using rope with marks or knots at The Pythagorean theorem shown graphically and 3-, 4-, and 5-space sections, and stretching mathematically the rope around carefully placed pegs driven into the ground. (See Figure 5-1.) In the sixth century BCE, the math- This method also works well for triangles ematician Pythagoras studied this method that have the same proportions, such as 6, 8, of forming right angles and proved the and 10 units: theory that the 3-4-5 triangle makes a right angle. This theorem (a2 + b2 = c2) or proof, 62 + 82 = 100 called the Pythagorean theorem, is shown in 36 + 64 = 100 Figure 5-2. 100 = 100 Figure 5-1 Egyptian rope-stretchers used knots divided into 3-4-5 triangles to lay out square corners for buildings. Section 5.1 Applied Geometry for Board Drafting 135 180° STRAIGHT LINE POINT OF RIGHT (SHORTEST DISTANCE INTERSECTION A ANGLE (90°) A BETWEEN TWO POINTS) B B INTERSECTING LINES SUPPLEMENTARY ANGLES PARALLEL LINES COMPLEMENTARY ANGLES HYPOTENUSE SIDE 60° SIDE SIDE SIDE ° 60° 60° ALTITUDE 90 EQUILATERAL TRIANGLE BASE SYMBOL FOR BASE ALL SIDES EQUAL LENGTH ISOSCELES TRIANGLE RIGHT ANGLE (90°) TWO SIDES EQUAL LENGTH SCALENE TRIANGLE SEMI-CIRCLE QUADRANT TANGENT ARC (ONE-QUARTER OF A CIRCLE) CHORD DIAMETER POINT OF TANGENCY RADIUS SECTOR TANGENT LINE SEGMENT ANGLE RIGHT ANGLES IN A SEMI-CIRCLE 5 SIDES 6 SIDES PENTAGON HEXAGON CONCENTRIC CIRCLES ECCENTRIC CIRCLES EQUAL OPPOSITE SIDES 7 SIDES 8 SIDES SIDES ARE EQUAL 90° ANGLES 90° ANGLES HEPTAGON OCTAGON SQUARE RECTANGLE EQUAL SIDES OPPOSITE SIDES ARE EQUAL 9 SIDES 10 SIDES OPPOSITE ANGLES OPPOSITE ANGLES ARE EQUAL ARE EQUAL RHOMBUS RHOMBOID NONAGON DECAGON TWO SIDES NO TWO SIDES 12 SIDES ARE PARALLEL ARE PARALLEL TRAPEZOID TRAPEZIUM DODECAGON Figure 5-3 Dictionary of drafting geometry 136 Chapter 5 Geometry for Drafting The units may be millimeters, meters, Illustrations made of individual lines and inches, fractions of an inch, or any other unit points drawn in proper relationship to one of measure. Geometric fi gures used in drafting another are known as geometric con- include circles, squares, triangles, hexagons, structions. Drafters, surveyors, engineers, and octagons. Many other shapes are shown architects, scientists, mathematicians, and in Figure 5-3. designers use geometric constructions. To understand geometric constructions, A2 ϩ B2 ϭ C2 you must understand how to describe various 32 ϩ 42 ϭ C2 lines, arcs, and other shapes. This chapter fol- 9 ϩ 16 ϭ 25 lows the identifi cation rules used in geometry. Geometry Formulas The diameter of a circle is 15″. What is the In addition to solving drafting problems circumference? using geometric constructions, drafters often To fi nd the circumference need to be able to calculate various aspects of of a circle, multiply pi (π) times the diam- geometric constructions. While hundreds of eter of the circle. The approximate decimal these formulas exist, a few are given here as equivalent of pi is 3.1416. examples. What is the area of triangle A where the base is Example: 10″ and the height is 7″? Circumference = πd Circumference = 3.1416 × 2.50 To fi nd the area of any tri- Circumference = 7.85 angle, multiply the base (b) times the height (h) and divide by two. DIAMETER (d) = 2.50 Example: Area = bh/2 Area = 2 × 6/2 Area = 6 square inches ALTITUDE (h) BASE (b) 2" For help with this math activity, go to the Math Appendix at the back of 6" this book. Academic Standards Mathematics Measurement Apply appropriate techniques, tools, and formulas to determine measurements (NCTM) Section 5.1 Applied Geometry for Board Drafting 137 Lines and arcs are described using their end- B AB points. Therefore, line AB is a line segment LINE AB ARC AB that extends from point A to point B. Arc AB A is an arc whose endpoints are A and B. Angles are described using three points: both end- A points and the vertex, or the point at which B A the two arms of the angle meet. Angle ABC is an angle whose endpoints are A and C and C ANGLE ABC CIRCLE A whose vertex is at point B. Circles are usually specifi ed using their center points, so circle Figure 5-4 A is a circle whose center is at point A. See Identifi cation of lines, angles, arcs, and circles Figure 5-4. Explain How is the Pythagorean theorem used in geometry? Bisect a Line, an Arc, or 2. With points A and B as centers and any radius R greater than one-half of AB, an Angle draw arcs to intersect, or cross, line AB Bisect means to divide into two equal parts. as in Figure 5-5B. The radius is the dis- tance from the center of an arc or circle to any point on the arc or circle. The two Bisect a Line or an Arc places where the arcs intersect create Follow these steps to bisect a straight line points C and D. or an arc. 3. Draw line EF through points C and D 1. Draw a line AB and arc AB as shown in (Figure 5-5C). Figure 5-5A. E A A R A R C C R R Figure 5-5 D D B B B Bisecting a straight line, F B B E B an arc, and an angle C C R R D R D A A A R F ABC 138 Chapter 5 Geometry for Drafting Bisect an Angle 3. With C and D as centers and any radius R more than one- half the radius of arc This construction demonstrates a method 2 CD, draw two arcs to intersect, locating for bisecting a given angle. Refer to Figure 5-6. point E. (Figure 5-6C). 1. Draw given angle AOB (Figure 5-6A). 4. Draw a line through points O and E to 2. With point O as the center and any con- bisect angle AOB (Figure 5-6C). venient radius R1, draw an arc to inter- sect AO and OB to locate points C and D (Figure 5-6B).
Load more

Recommended publications
  • THE GEOMETRY of PYRAMIDS One of the More Interesting Solid
    THE GEOMETRY OF PYRAMIDS One of the more interesting solid structures which has fascinated individuals for thousands of years going all the way back to the ancient Egyptians is the pyramid. It is a structure in which one takes a closed curve in the x-y plane and connects straight lines between every point on this curve and a fixed point P above the centroid of the curve. Classical pyramids such as the structures at Giza have square bases and lateral sides close in form to equilateral triangles. When the closed curve becomes a circle one obtains a cone and this cone becomes a cylindrical rod when point P is moved to infinity. It is our purpose here to discuss the properties of all N sided pyramids including their volume and surface area using only elementary calculus and geometry. Our starting point will be the following sketch- The base represents a regular N sided polygon with side length ‘a’ . The angle between neighboring radial lines r (shown in red) connecting the polygon vertices with its centroid is θ=2π/N. From this it follows, by the law of cosines, that the length r=a/sqrt[2(1- cos(θ))] . The area of the iscosolis triangle of sides r-a-r is- a a 2 a 2 1 cos( ) A r 2 T 2 4 4 (1 cos( ) From this we have that the area of the N sided polygon and hence the pyramid base will be- 2 2 1 cos( ) Na A N base 2 4 1 cos( ) N 2 It readily follows from this result that a square base N=4 has area Abase=a and a hexagon 2 base N=6 yields Abase= 3sqrt(3)a /2.
    [Show full text]
  • Lateral and Surface Area of Right Prisms 1 Jorge Is Trying to Wrap a Present That Is in a Box Shaped As a Right Prism
    CHAPTER 11 You will need Lateral and Surface • a ruler A • a calculator Area of Right Prisms c GOAL Calculate lateral area and surface area of right prisms. Learn about the Math A prism is a polyhedron (solid whose faces are polygons) whose bases are congruent and parallel. When trying to identify a right prism, ask yourself if this solid could have right prism been created by placing many congruent sheets of paper on prism that has bases aligned one above the top of each other. If so, this is a right prism. Some examples other and has lateral of right prisms are shown below. faces that are rectangles Triangular prism Rectangular prism The surface area of a right prism can be calculated using the following formula: SA 5 2B 1 hP, where B is the area of the base, h is the height of the prism, and P is the perimeter of the base. The lateral area of a figure is the area of the non-base faces lateral area only. When a prism has its bases facing up and down, the area of the non-base faces of a figure lateral area is the area of the vertical faces. (For a rectangular prism, any pair of opposite faces can be bases.) The lateral area of a right prism can be calculated by multiplying the perimeter of the base by the height of the prism. This is summarized by the formula: LA 5 hP. Copyright © 2009 by Nelson Education Ltd. Reproduction permitted for classrooms 11A Lateral and Surface Area of Right Prisms 1 Jorge is trying to wrap a present that is in a box shaped as a right prism.
    [Show full text]
  • Descriptive Geometry Section 10.1 Basic Descriptive Geometry and Board Drafting Section 10.2 Solving Descriptive Geometry Problems with CAD
    10 Descriptive Geometry Section 10.1 Basic Descriptive Geometry and Board Drafting Section 10.2 Solving Descriptive Geometry Problems with CAD Chapter Objectives • Locate points in three-dimensional (3D) space. • Identify and describe the three basic types of lines. • Identify and describe the three basic types of planes. • Solve descriptive geometry problems using board-drafting techniques. • Create points, lines, planes, and solids in 3D space using CAD. • Solve descriptive geometry problems using CAD. Plane Spoken Rutan’s unconventional 202 Boomerang aircraft has an asymmetrical design, with one engine on the fuselage and another mounted on a pod. What special allowances would need to be made for such a design? 328 Drafting Career Burt Rutan, Aeronautical Engineer Effi cient travel through space has become an ambi- tion of aeronautical engineer, Burt Rutan. “I want to go high,” he says, “because that’s where the view is.” His unconventional designs have included every- thing from crafts that can enter space twice within a two week period, to planes than can circle the Earth without stopping to refuel. Designed by Rutan and built at his company, Scaled Composites LLC, the 202 Boomerang aircraft is named for its forward-swept asymmetrical wing. The design allows the Boomerang to fl y faster and farther than conventional twin-engine aircraft, hav- ing corrected aerodynamic mistakes made previously in twin-engine design. It is hailed as one of the most beautiful aircraft ever built. Academic Skills and Abilities • Algebra, geometry, calculus • Biology, chemistry, physics • English • Social studies • Humanities • Computer use Career Pathways Engineers should be creative, inquisitive, ana- lytical, detail oriented, and able to work as part of a team and to communicate well.
    [Show full text]
  • 1-1 Understanding Points, Lines, and Planes Lines, and Planes
    Understanding Points, 1-11-1 Understanding Points, Lines, and Planes Lines, and Planes Holt Geometry 1-1 Understanding Points, Lines, and Planes Objectives Identify, name, and draw points, lines, segments, rays, and planes. Apply basic facts about points, lines, and planes. Holt Geometry 1-1 Understanding Points, Lines, and Planes Vocabulary undefined term point line plane collinear coplanar segment endpoint ray opposite rays postulate Holt Geometry 1-1 Understanding Points, Lines, and Planes The most basic figures in geometry are undefined terms, which cannot be defined by using other figures. The undefined terms point, line, and plane are the building blocks of geometry. Holt Geometry 1-1 Understanding Points, Lines, and Planes Holt Geometry 1-1 Understanding Points, Lines, and Planes Points that lie on the same line are collinear. K, L, and M are collinear. K, L, and N are noncollinear. Points that lie on the same plane are coplanar. Otherwise they are noncoplanar. K L M N Holt Geometry 1-1 Understanding Points, Lines, and Planes Example 1: Naming Points, Lines, and Planes A. Name four coplanar points. A, B, C, D B. Name three lines. Possible answer: AE, BE, CE Holt Geometry 1-1 Understanding Points, Lines, and Planes Holt Geometry 1-1 Understanding Points, Lines, and Planes Example 2: Drawing Segments and Rays Draw and label each of the following. A. a segment with endpoints M and N. N M B. opposite rays with a common endpoint T. T Holt Geometry 1-1 Understanding Points, Lines, and Planes Check It Out! Example 2 Draw and label a ray with endpoint M that contains N.
    [Show full text]
  • Machine Drawing
    2.4 LINES Lines of different types and thicknesses are used for graphical representation of objects. The types of lines and their applications are shown in Table 2.4. Typical applications of different types of lines are shown in Figs. 2.5 and 2.6. Table 2.4 Types of lines and their applications Line Description General Applications A Continuous thick A1 Visible outlines B Continuous thin B1 Imaginary lines of intersection (straight or curved) B2 Dimension lines B3 Projection lines B4 Leader lines B5 Hatching lines B6 Outlines of revolved sections in place B7 Short centre lines C Continuous thin, free-hand C1 Limits of partial or interrupted views and sections, if the limit is not a chain thin D Continuous thin (straight) D1 Line (see Fig. 2.5) with zigzags E Dashed thick E1 Hidden outlines G Chain thin G1 Centre lines G2 Lines of symmetry G3 Trajectories H Chain thin, thick at ends H1 Cutting planes and changes of direction J Chain thick J1 Indication of lines or surfaces to which a special requirement applies K Chain thin, double-dashed K1 Outlines of adjacent parts K2 Alternative and extreme positions of movable parts K3 Centroidal lines 2.4.2 Order of Priority of Coinciding Lines When two or more lines of different types coincide, the following order of priority should be observed: (i) Visible outlines and edges (Continuous thick lines, type A), (ii) Hidden outlines and edges (Dashed line, type E or F), (iii) Cutting planes (Chain thin, thick at ends and changes of cutting planes, type H), (iv) Centre lines and lines of symmetry (Chain thin line, type G), (v) Centroidal lines (Chain thin double dashed line, type K), (vi) Projection lines (Continuous thin line, type B).
    [Show full text]
  • Pentagonal Pyramid
    Chapter 9 Surfaces and Solids Copyright © Cengage Learning. All rights reserved. Pyramids, Area, and 9.2 Volume Copyright © Cengage Learning. All rights reserved. Pyramids, Area, and Volume The solids (space figures) shown in Figure 9.14 below are pyramids. In Figure 9.14(a), point A is noncoplanar with square base BCDE. In Figure 9.14(b), F is noncoplanar with its base, GHJ. (a) (b) Figure 9.14 3 Pyramids, Area, and Volume In each space pyramid, the noncoplanar point is joined to each vertex as well as each point of the base. A solid pyramid results when the noncoplanar point is joined both to points on the polygon as well as to points in its interior. Point A is known as the vertex or apex of the square pyramid; likewise, point F is the vertex or apex of the triangular pyramid. The pyramid of Figure 9.14(b) has four triangular faces; for this reason, it is called a tetrahedron. 4 Pyramids, Area, and Volume The pyramid in Figure 9.15 is a pentagonal pyramid. It has vertex K, pentagon LMNPQ for its base, and lateral edges and Although K is called the vertex of the pyramid, there are actually six vertices: K, L, M, N, P, and Q. Figure 9.15 The sides of the base and are base edges. 5 Pyramids, Area, and Volume All lateral faces of a pyramid are triangles; KLM is one of the five lateral faces of the pentagonal pyramid. Including base LMNPQ, this pyramid has a total of six faces. The altitude of the pyramid, of length h, is the line segment from the vertex K perpendicular to the plane of the base.
    [Show full text]
  • A Historical Introduction to Elementary Geometry
    i MATH 119 – Fall 2012: A HISTORICAL INTRODUCTION TO ELEMENTARY GEOMETRY Geometry is an word derived from ancient Greek meaning “earth measure” ( ge = earth or land ) + ( metria = measure ) . Euclid wrote the Elements of geometry between 330 and 320 B.C. It was a compilation of the major theorems on plane and solid geometry presented in an axiomatic style. Near the beginning of the first of the thirteen books of the Elements, Euclid enumerated five fundamental assumptions called postulates or axioms which he used to prove many related propositions or theorems on the geometry of two and three dimensions. POSTULATE 1. Any two points can be joined by a straight line. POSTULATE 2. Any straight line segment can be extended indefinitely in a straight line. POSTULATE 3. Given any straight line segment, a circle can be drawn having the segment as radius and one endpoint as center. POSTULATE 4. All right angles are congruent. POSTULATE 5. (Parallel postulate) If two lines intersect a third in such a way that the sum of the inner angles on one side is less than two right angles, then the two lines inevitably must intersect each other on that side if extended far enough. The circle described in postulate 3 is tacitly unique. Postulates 3 and 5 hold only for plane geometry; in three dimensions, postulate 3 defines a sphere. Postulate 5 leads to the same geometry as the following statement, known as Playfair's axiom, which also holds only in the plane: Through a point not on a given straight line, one and only one line can be drawn that never meets the given line.
    [Show full text]
  • Geometry Course Outline
    GEOMETRY COURSE OUTLINE Content Area Formative Assessment # of Lessons Days G0 INTRO AND CONSTRUCTION 12 G-CO Congruence 12, 13 G1 BASIC DEFINITIONS AND RIGID MOTION Representing and 20 G-CO Congruence 1, 2, 3, 4, 5, 6, 7, 8 Combining Transformations Analyzing Congruency Proofs G2 GEOMETRIC RELATIONSHIPS AND PROPERTIES Evaluating Statements 15 G-CO Congruence 9, 10, 11 About Length and Area G-C Circles 3 Inscribing and Circumscribing Right Triangles G3 SIMILARITY Geometry Problems: 20 G-SRT Similarity, Right Triangles, and Trigonometry 1, 2, 3, Circles and Triangles 4, 5 Proofs of the Pythagorean Theorem M1 GEOMETRIC MODELING 1 Solving Geometry 7 G-MG Modeling with Geometry 1, 2, 3 Problems: Floodlights G4 COORDINATE GEOMETRY Finding Equations of 15 G-GPE Expressing Geometric Properties with Equations 4, 5, Parallel and 6, 7 Perpendicular Lines G5 CIRCLES AND CONICS Equations of Circles 1 15 G-C Circles 1, 2, 5 Equations of Circles 2 G-GPE Expressing Geometric Properties with Equations 1, 2 Sectors of Circles G6 GEOMETRIC MEASUREMENTS AND DIMENSIONS Evaluating Statements 15 G-GMD 1, 3, 4 About Enlargements (2D & 3D) 2D Representations of 3D Objects G7 TRIONOMETRIC RATIOS Calculating Volumes of 15 G-SRT Similarity, Right Triangles, and Trigonometry 6, 7, 8 Compound Objects M2 GEOMETRIC MODELING 2 Modeling: Rolling Cups 10 G-MG Modeling with Geometry 1, 2, 3 TOTAL: 144 HIGH SCHOOL OVERVIEW Algebra 1 Geometry Algebra 2 A0 Introduction G0 Introduction and A0 Introduction Construction A1 Modeling With Functions G1 Basic Definitions and Rigid
    [Show full text]
  • 13 Graphs 13.2D Lengths of Line Segments
    MEP Pupil Text 13-19, Additional Material 13 Graphs 13.2D Lengths of Line Segments In a right-angled triangle the length of the hypotenuse may be calculated using Pythagoras' Theorem. c b cab222=+ a Worked Example 1 Determine the length of the line segment joining the points A (4, 1) and B (10, 9). Solution y (a) The diagram shows the two points and the line segment that joins them. 10 B A right-angled triangle has been 9 drawn under the line segment. The 8 length of the line segment AB (the 7 hypotenuse) may be found by using 6 Pythagoras' Theorem. 5 8 4 AB2 =+62 82 3 2 =+ 2 AB 36 64 A 6 1 AB2 = 100 0 12345678910 x AB = 100 AB = 10 Worked Example 2 y C Determine the length of the line 8 7 joining the points C (−48, ) 6 (−) and D 86, . 5 4 Solution 3 2 14 The diagram shows the two points 1 and a right-angled triangle that can –4 –3 –2 –1 0 12345678 x be used to determine the length of –1 the line segment CD. –2 –3 –4 –5 D –6 12 1 13.2D MEP Pupil Text 13-19, Additional Material Using Pythagoras' Theorem, CD2 =+142 122 CD2 =+196 144 CD2 = 340 CD = 340 CD = 18. 43908891 CD = 18. 4 (to 3 significant figures) Exercises 1. The diagram shows the three points y C A, B and C which are the vertices 11 of a triangle. 10 9 (a) State the length of the line 8 segment AB.
    [Show full text]
  • Module-03 / Lecture-01 SOLIDS Introduction- This Chapter Deals with the Orthographic Projections of Three – Dimensional Objects Called Solids
    1 Module-03 / Lecture-01 SOLIDS Introduction- This chapter deals with the orthographic projections of three – dimensional objects called solids. However, only those solids are considered the shape of which can be defined geometrically and are regular in nature. To understand and remember various solids in this subject properly, those are classified & arranged in to two major groups- Polyhedron- A polyhedron is defined as a solid bounded by planes called faces, which meet in straight lines called edges. Regular Polyhedron- It is polyhedron, having all the faces equal and regular. Tetrahedron- It is a solid, having four equal equilateral triangular faces. Cube- It is a solid, having six equal square faces. Octahedron- It is a solid, having eight equal equilateral triangular faces. Dodecahedron- It is a solid, having twelve equal pentagonal faces. Icosahedrons- It is a solid, having twenty equal equilateral triangular faces. Prism- This is a polyhedron, having two equal and similar regular polygons called its ends or bases, parallel to each other and joined by other faces which are rectangles. The imaginary line joining the centre of the bases is called the axis. A right and regular prism has its axis perpendicular to the base. All the faces are equal rectangles. 1 2 Pyramid- This is a polyhedron, having a regular polygon as a base and a number of triangular faces meeting at a point called the vertex or apex. The imaginary line joining the apex with the centre of the base is known as the axis. A right and regular pyramid has its axis perpendicular to the base which is a regular plane.
    [Show full text]
  • Apollonius of Pergaconics. Books One - Seven
    APOLLONIUS OF PERGACONICS. BOOKS ONE - SEVEN INTRODUCTION A. Apollonius at Perga Apollonius was born at Perga (Περγα) on the Southern coast of Asia Mi- nor, near the modern Turkish city of Bursa. Little is known about his life before he arrived in Alexandria, where he studied. Certain information about Apollonius’ life in Asia Minor can be obtained from his preface to Book 2 of Conics. The name “Apollonius”(Apollonius) means “devoted to Apollo”, similarly to “Artemius” or “Demetrius” meaning “devoted to Artemis or Demeter”. In the mentioned preface Apollonius writes to Eudemus of Pergamum that he sends him one of the books of Conics via his son also named Apollonius. The coincidence shows that this name was traditional in the family, and in all prob- ability Apollonius’ ancestors were priests of Apollo. Asia Minor during many centuries was for Indo-European tribes a bridge to Europe from their pre-fatherland south of the Caspian Sea. The Indo-European nation living in Asia Minor in 2nd and the beginning of the 1st millennia B.C. was usually called Hittites. Hittites are mentioned in the Bible and in Egyptian papyri. A military leader serving under the Biblical king David was the Hittite Uriah. His wife Bath- sheba, after his death, became the wife of king David and the mother of king Solomon. Hittites had a cuneiform writing analogous to the Babylonian one and hi- eroglyphs analogous to Egyptian ones. The Czech historian Bedrich Hrozny (1879-1952) who has deciphered Hittite cuneiform writing had established that the Hittite language belonged to the Western group of Indo-European languages [Hro].
    [Show full text]
  • Geometry by Its History
    Undergraduate Texts in Mathematics Geometry by Its History Bearbeitet von Alexander Ostermann, Gerhard Wanner 1. Auflage 2012. Buch. xii, 440 S. Hardcover ISBN 978 3 642 29162 3 Format (B x L): 15,5 x 23,5 cm Gewicht: 836 g Weitere Fachgebiete > Mathematik > Geometrie > Elementare Geometrie: Allgemeines Zu Inhaltsverzeichnis schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, eBooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte. 2 The Elements of Euclid “At age eleven, I began Euclid, with my brother as my tutor. This was one of the greatest events of my life, as dazzling as first love. I had not imagined that there was anything as delicious in the world.” (B. Russell, quoted from K. Hoechsmann, Editorial, π in the Sky, Issue 9, Dec. 2005. A few paragraphs later K. H. added: An innocent look at a page of contemporary the- orems is no doubt less likely to evoke feelings of “first love”.) “At the age of 16, Abel’s genius suddenly became apparent. Mr. Holmbo¨e, then professor in his school, gave him private lessons. Having quickly absorbed the Elements, he went through the In- troductio and the Institutiones calculi differentialis and integralis of Euler. From here on, he progressed alone.” (Obituary for Abel by Crelle, J. Reine Angew. Math. 4 (1829) p. 402; transl. from the French) “The year 1868 must be characterised as [Sophus Lie’s] break- through year.
    [Show full text]