Applied Mathematics, Fourth Edition II Contents
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Polygon Review and Puzzlers in the Above, Those Are Names to the Polygons: Fill in the Blank Parts. Names: Number of Sides
Polygon review and puzzlers ÆReview to the classification of polygons: Is it a Polygon? Polygons are 2-dimensional shapes. They are made of straight lines, and the shape is "closed" (all the lines connect up). Polygon Not a Polygon Not a Polygon (straight sides) (has a curve) (open, not closed) Regular polygons have equal length sides and equal interior angles. Polygons are named according to their number of sides. Name of Degree of Degree of triangle total angles regular angles Triangle 180 60 In the above, those are names to the polygons: Quadrilateral 360 90 fill in the blank parts. Pentagon Hexagon Heptagon 900 129 Names: number of sides: Octagon Nonagon hendecagon, 11 dodecagon, _____________ Decagon 1440 144 tetradecagon, 13 hexadecagon, 15 Do you see a pattern in the calculation of the heptadecagon, _____________ total degree of angles of the polygon? octadecagon, _____________ --- (n -2) x 180° enneadecagon, _____________ icosagon 20 pentadecagon, _____________ These summation of angles rules, also apply to the irregular polygons, try it out yourself !!! A point where two or more straight lines meet. Corner. Example: a corner of a polygon (2D) or of a polyhedron (3D) as shown. The plural of vertex is "vertices” Test them out yourself, by drawing diagonals on the polygons. Here are some fun polygon riddles; could you come up with the answer? Geometry polygon riddles I: My first is in shape and also in space; My second is in line and also in place; My third is in point and also in line; My fourth in operation but not in sign; My fifth is in angle but not in degree; My sixth is in glide but not symmetry; Geometry polygon riddles II: I am a polygon all my angles have the same measure all my five sides have the same measure, what general shape am I? Geometry polygon riddles III: I am a polygon. -
Properties of N-Sided Regular Polygons
PROPERTIES OF N-SIDED REGULAR POLYGONS When students are first exposed to regular polygons in middle school, they learn their properties by looking at individual examples such as the equilateral triangles(n=3), squares(n=4), and hexagons(n=6). A generalization is usually not given, although it would be straight forward to do so with just a min imum of trigonometry and algebra. It also would help students by showing how one obtains generalization in mathematics. We show here how to carry out such a generalization for regular polynomials of side length s. Our starting point is the following schematic of an n sided polygon- We see from the figure that any regular n sided polygon can be constructed by looking at n isosceles triangles whose base angles are θ=(1-2/n)(π/2) since the vertex angle of the triangle is just ψ=2π/n, when expressed in radians. The area of the grey triangle in the above figure is- 2 2 ATr=sh/2=(s/2) tan(θ)=(s/2) tan[(1-2/n)(π/2)] so that the total area of any n sided regular convex polygon will be nATr, , with s again being the side-length. With this generalized form we can construct the following table for some of the better known regular polygons- Name Number of Base Angle, Non-Dimensional 2 sides, n θ=(π/2)(1-2/n) Area, 4nATr/s =tan(θ) Triangle 3 π/6=30º 1/sqrt(3) Square 4 π/4=45º 1 Pentagon 5 3π/10=54º sqrt(15+20φ) Hexagon 6 π/3=60º sqrt(3) Octagon 8 3π/8=67.5º 1+sqrt(2) Decagon 10 2π/5=72º 10sqrt(3+4φ) Dodecagon 12 5π/12=75º 144[2+sqrt(3)] Icosagon 20 9π/20=81º 20[2φ+sqrt(3+4φ)] Here φ=[1+sqrt(5)]/2=1.618033989… is the well known Golden Ratio. -
Formulas Involving Polygons - Lesson 7-3
you are here > Class Notes – Chapter 7 – Lesson 7-3 Formulas Involving Polygons - Lesson 7-3 Here’s today’s warmup…don’t forget to “phone home!” B Given: BD bisects ∠PBQ PD ⊥ PB QD ⊥ QB M Prove: BD is ⊥ bis. of PQ P Q D Statements Reasons Honors Geometry Notes Today, we started by learning how polygons are classified by their number of sides...you should already know a lot of these - just make sure to memorize the ones you don't know!! Sides Name 3 Triangle 4 Quadrilateral 5 Pentagon 6 Hexagon 7 Heptagon 8 Octagon 9 Nonagon 10 Decagon 11 Undecagon 12 Dodecagon 13 Tridecagon 14 Tetradecagon 15 Pentadecagon 16 Hexadecagon 17 Heptadecagon 18 Octadecagon 19 Enneadecagon 20 Icosagon n n-gon Baroody Page 2 of 6 Honors Geometry Notes Next, let’s look at the diagonals of polygons with different numbers of sides. By drawing as many diagonals as we could from one diagonal, you should be able to see a pattern...we can make n-2 triangles in a n-sided polygon. Given this information and the fact that the sum of the interior angles of a polygon is 180°, we can come up with a theorem that helps us to figure out the sum of the measures of the interior angles of any n-sided polygon! Baroody Page 3 of 6 Honors Geometry Notes Next, let’s look at exterior angles in a polygon. First, consider the exterior angles of a pentagon as shown below: Note that the sum of the exterior angles is 360°. -
Geometric Constructions of Regular Polygons and Applications to Trigonometry Introduction
Geometric Constructions of Regular Polygons and Applications to Trigonometry José Gilvan de Oliveira, Moacir Rosado Filho, Domingos Sávio Valério Silva Abstract: In this paper, constructions of regular pentagon and decagon, and the calculation of the main trigonometric ratios of the corresponding central angles are approached. In this way, for didactic purposes, it is intended to show the reader that it is possible to broaden the study of Trigonometry by addressing new applications and exercises, for example, with angles 18°, 36° and 72°. It is also considered constructions of other regular polygons and a relation to a construction of the regular icosahedron. Introduction The main objective of this paper is to approach regular pentagon and decagon constructions, together with the calculation of the main trigonometric ratios of the corresponding central angles. In textbooks, examples and exercises involving trigonometric ratios are usually restricted to so-called notable arcs of angles 30°, 45° and 60°. Although these angles are not the main purpose of this article, they will be addressed because the ingredients used in these cases are exactly the same as those we will use to build the regular pentagon and decagon. The difference to the construction of these last two is restricted only to the number of steps required throughout the construction process. By doing so, we intend to show the reader that it is possible to broaden the study of Trigonometry by addressing new applications and exercises, for example, with angles 18°, 36° and 72°. The ingredients used in the text are those found in Plane Geometry and are very few, restricted to intersections of lines and circumferences, properties of triangles, and Pythagorean Theorem. -
Towards Van Der Laan's Plastic Number in the Plane
Journal for Geometry and Graphics Volume 13 (2009), No. 2, 163–175. Towards van der Laan’s Plastic Number in the Plane Vera W. de Spinadel1, Antonia Redondo Buitrago2 1Laboratorio de Matem´atica y Dise˜no, Universidad de Buenos Aires Buenos Aires, Argentina email: vspinadel@fibertel.com.ar 2Departamento de Matem´atica, I.E.S. Bachiller Sabuco Avenida de Espa˜na 9, 02002 Albacete, Espa˜na email: [email protected] Abstract. In 1960 D.H. van der Laan, architect and member of the Benedic- tine order, introduced what he calls the “Plastic Number” ψ, as an ideal ratio for a geometric scale of spatial objects. It is the real solution of the cubic equation x3 x 1 = 0. This equation may be seen as example of a family of trinomials − − xn x 1=0, n =2, 3,... Considering the real positive roots of these equations we− define− these roots as members of a “Plastic Numbers Family” (PNF) com- prising the well known Golden Mean φ = 1, 618..., the most prominent member of the Metallic Means Family [12] and van der Laan’s Number ψ = 1, 324... Similar to the occurrence of φ in art and nature one can use ψ for defining special 2D- and 3D-objects (rectangles, trapezoids, ellipses, ovals, ovoids, spirals and even 3D-boxes) and look for natural representations of this special number. Laan’s Number ψ and the Golden Number φ are the only “Morphic Numbers” in the sense of Aarts et al. [1], who define such a number as the common solution of two somehow dual trinomials. -
Volume 2 Shape and Space
Volume 2 Shape and Space Colin Foster Introduction Teachers are busy people, so I’ll be brief. Let me tell you what this book isn’t. • It isn’t a book you have to make time to read; it’s a book that will save you time. Take it into the classroom and use ideas from it straight away. Anything requiring preparation or equipment (e.g., photocopies, scissors, an overhead projector, etc.) begins with the word “NEED” in bold followed by the details. • It isn’t a scheme of work, and it isn’t even arranged by age or pupil “level”. Many of the ideas can be used equally well with pupils at different ages and stages. Instead the items are simply arranged by topic. (There is, however, an index at the back linking the “key objectives” from the Key Stage 3 Framework to the sections in these three volumes.) The three volumes cover Number and Algebra (1), Shape and Space (2) and Probability, Statistics, Numeracy and ICT (3). • It isn’t a book of exercises or worksheets. Although you’re welcome to photocopy anything you wish, photocopying is expensive and very little here needs to be photocopied for pupils. Most of the material is intended to be presented by the teacher orally or on the board. Answers and comments are given on the right side of most of the pages or sometimes on separate pages as explained. This is a book to make notes in. Cross out anything you don’t like or would never use. Add in your own ideas or references to other resources. -
Parallelogram Rhombus Nonagon Hexagon Icosagon Tetrakaidecagon Hexakaidecagon Quadrilateral Ellipse Scalene T
Call List parallelogram rhombus nonagon hexagon icosagon tetrakaidecagon hexakaidecagon quadrilateral ellipse scalene triangle square rectangle hendecagon pentagon dodecagon decagon trapezium / trapezoid right triangle equilateral triangle circle octagon heptagon isosceles triangle pentadecagon triskaidecagon Created using www.BingoCardPrinter.com B I N G O parallelogram tetrakaidecagon square dodecagon circle rhombus hexakaidecagon rectangle decagon octagon Free trapezium / nonagon quadrilateral heptagon Space trapezoid right isosceles hexagon hendecagon ellipse triangle triangle scalene equilateral icosagon pentagon pentadecagon triangle triangle Created using www.BingoCardPrinter.com B I N G O pentagon rectangle pentadecagon triskaidecagon hexakaidecagon equilateral scalene nonagon parallelogram circle triangle triangle isosceles Free trapezium / octagon triangle Space square trapezoid ellipse heptagon rhombus tetrakaidecagon icosagon right decagon hendecagon dodecagon hexagon triangle Created using www.BingoCardPrinter.com B I N G O right decagon triskaidecagon hendecagon dodecagon triangle trapezium / scalene pentagon square trapezoid triangle circle Free tetrakaidecagon octagon quadrilateral ellipse Space isosceles parallelogram hexagon hexakaidecagon nonagon triangle equilateral pentadecagon rectangle icosagon heptagon triangle Created using www.BingoCardPrinter.com B I N G O equilateral trapezium / pentagon pentadecagon dodecagon triangle trapezoid rectangle rhombus quadrilateral nonagon octagon isosceles Free scalene hendecagon -
Metallic Means : Beyond the Golden Ratio, New Mathematics And
Journal of Advances in Mathematics Vol 20 (2021) ISSN: 2347-1921 https://rajpub.com/index.php/jam DOI: https://doi.org/10.24297/jam.v20i.9056 Metallic Means : Beyond the Golden Ratio, New Mathematics and Geometry of all Metallic Ratios based upon Right Triangles, The Formation of the “Triads” of Metallic Means, And their Classical Correspondence with Pythagorean Triples and p≡1(mod 4) Primes, Also the Correlation between Metallic Numbers and the Digits 3 6 9, Triangles – Triads – Triples - & 3 6 9 Dr. Chetansing Rajput M.B.B.S. Nair Hospital (Mumbai University) India, Asst. Commissioner (Govt. of Maharashtra) Lecture Link: https://youtu.be/vBfVDaFnA2k Email: [email protected] Website: https://goldenratiorajput.com/ Abstract This paper brings together the newly discovered generalised geometry of all Metallic Means and the recently published mathematical formulae those provide the precise correlations between different Metallic Ratios. The paper also puts forward the concept of the “Triads of Metallic Means”. This work also introduces the close correspondence between Metallic Ratios and the Pythagorean Triples as well as Pythagorean Primes. Moreover, this work illustrates the intriguing relationship between Metallic Numbers and the Digits 3 6 9. Keywords: Fibonacci sequence, Pi, Phi, Pythagoras Theorem, Divine Proportion, Silver Ratio, Golden Mean, Right Triangle, Metallic Numbers, Pell Numbers, Lucas Numbers, Golden Proportion, Metallic Ratio, Metallic Triples, 3 6 9, Pythagorean Triples, Pythagorean Primes, Golden Ratio, Metallic Mean Introduction The prime objective of this work is to synergize the following couple of newly discovered aspects of Metallic Means: 1) The Generalised Geometric Construction of all Metallic Ratios: cited by Wikipedia in its page on “Metallic Mean”[1]. -
Metallic Ratios in Primitive Pythagorean Triples : Metallic Means Embedded in Pythagorean Triangles and Other Right Triangles
Journal of Advances in Mathematics Vol 20 (2021) ISSN: 2347-1921 https://rajpub.com/index.php/jam DOI: https://doi.org/10.24297/jam.v20i.9088 Metallic Ratios in Primitive Pythagorean Triples : Metallic Means embedded in Pythagorean Triangles and other Right Triangles Dr. Chetansing Rajput M.B.B.S. Nair Hospital (Mumbai University) India, Asst. Commissioner (Govt. of Maharashtra) Email: [email protected] Website: https://goldenratiorajput.com/ Lecture Link 1 : https://youtu.be/LFW1saNOp20 Lecture Link 2 : https://youtu.be/vBfVDaFnA2k Lecture Link 3 : https://youtu.be/raosniXwRhw Lecture Link 4 : https://youtu.be/74uF4sBqYjs Lecture Link 5 : https://youtu.be/Qh2B1tMl8Bk Abstract The Primitive Pythagorean Triples are found to be the purest expressions of various Metallic Ratios. Each Metallic Mean is epitomized by one particular Pythagorean Triangle. Also, the Right Angled Triangles are found to be more “Metallic” than the Pentagons, Octagons or any other (n2+4)gons. The Primitive Pythagorean Triples, not the regular polygons, are the prototypical forms of all Metallic Means. Keywords: Metallic Mean, Pythagoras Theorem, Right Triangle, Metallic Ratio Triads, Pythagorean Triples, Golden Ratio, Pascal’s Triangle, Pythagorean Triangles, Metallic Ratio A Primitive Pythagorean Triple for each Metallic Mean (훅n) : Author’s previous paper titled “Golden Ratio” cited by the Wikipedia page on “Metallic Mean” [1] & [2], among other works mentioned in the References, have already highlighted the underlying proposition that the Metallic Means -
From One Polygon to Another: a Distinctive Feature of Some Ottoman Minarets
Bernard Parzysz Research Université d’Orléans (France) From One Polygon to Another: Laboratoire André-Revuz Université Paris-Diderot A Distinctive Feature of Some 22 avenue du Général Leclerc Ottoman Minarets 92260 Fontenay-aux-Roses FRANCE Abstract. This article is a geometer’s reflection on a specificity [email protected] presented by some Turkish minarets erected during the Ottoman period which gives them a recognisable appearance. Keywords: Ottoman The intermediate zone (pabuç) between the shaft and the architecture, minarets, base of these minarets, which has both a functional and an polyhedra, Turkish triangles aesthetic function, is also an answer to the problem of connecting two prismatic solids having an unequal number of lateral sides (namely, two different multiples of 4). In the present case this connection was achieved by creating a polyhedron, the lateral sides of which are triangles placed head to tail. The multiple variables of the problem allowed the Ottoman architects to produce various solutions. 1 Introduction Each religion developed specific places for worship: synagogues, temples, churches, mosques, and so forth, and the rites and ceremonies for which they were designed conditioned their architecture. Mosques are associated with Islam, and are most certainly perceived throughout the world as its most typical monuments. They accompanied very early the history of this religion, but one of their most emblematic features, the minaret, did not appear immediately and when they did, specificities occurred depending on the period and geographic and cultural area they were built in. As Auguste Choisy writes in his Histoire de l’architecture: “Minarets have their own geography, just as steeples have theirs”. -
Euclidean Geometry
Euclidean Geometry Rich Cochrane Andrew McGettigan Fine Art Maths Centre Central Saint Martins http://maths.myblog.arts.ac.uk/ Reviewer: Prof Jeremy Gray, Open University October 2015 www.mathcentre.co.uk This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. 2 Contents Introduction 5 What's in this Booklet? 5 To the Student 6 To the Teacher 7 Toolkit 7 On Geogebra 8 Acknowledgements 10 Background Material 11 The Importance of Method 12 First Session: Tools, Methods, Attitudes & Goals 15 What is a Construction? 15 A Note on Lines 16 Copy a Line segment & Draw a Circle 17 Equilateral Triangle 23 Perpendicular Bisector 24 Angle Bisector 25 Angle Made by Lines 26 The Regular Hexagon 27 © Rich Cochrane & Andrew McGettigan Reviewer: Jeremy Gray www.mathcentre.co.uk Central Saint Martins, UAL Open University 3 Second Session: Parallel and Perpendicular 30 Addition & Subtraction of Lengths 30 Addition & Subtraction of Angles 33 Perpendicular Lines 35 Parallel Lines 39 Parallel Lines & Angles 42 Constructing Parallel Lines 44 Squares & Other Parallelograms 44 Division of a Line Segment into Several Parts 50 Thales' Theorem 52 Third Session: Making Sense of Area 53 Congruence, Measurement & Area 53 Zero, One & Two Dimensions 54 Congruent Triangles 54 Triangles & Parallelograms 56 Quadrature 58 Pythagoras' Theorem 58 A Quadrature Construction 64 Summing the Areas of Squares 67 Fourth Session: Tilings 69 The Idea of a Tiling 69 Euclidean & Related Tilings 69 Islamic Tilings 73 Further Tilings -
Wythoffian Skeletal Polyhedra
Wythoffian Skeletal Polyhedra by Abigail Williams B.S. in Mathematics, Bates College M.S. in Mathematics, Northeastern University A dissertation submitted to The Faculty of the College of Science of Northeastern University in partial fulfillment of the requirements for the degree of Doctor of Philosophy April 14, 2015 Dissertation directed by Egon Schulte Professor of Mathematics Dedication I would like to dedicate this dissertation to my Meme. She has always been my loudest cheerleader and has supported me in all that I have done. Thank you, Meme. ii Abstract of Dissertation Wythoff's construction can be used to generate new polyhedra from the symmetry groups of the regular polyhedra. In this dissertation we examine all polyhedra that can be generated through this construction from the 48 regular polyhedra. We also examine when the construction produces uniform polyhedra and then discuss other methods for finding uniform polyhedra. iii Acknowledgements I would like to start by thanking Professor Schulte for all of the guidance he has provided me over the last few years. He has given me interesting articles to read, provided invaluable commentary on this thesis, had many helpful and insightful discussions with me about my work, and invited me to wonderful conferences. I truly cannot thank him enough for all of his help. I am also very thankful to my committee members for their time and attention. Additionally, I want to thank my family and friends who, for years, have supported me and pretended to care everytime I start talking about math. Finally, I want to thank my husband, Keith.