8.2 Perimeters Of Composite Figures - Big Ideas Learning
8.2Perimeters of Composite FiguresHow can you find the perimeter of acomposite figure?1ACTIVITY: Finding a PatternWork with a partner. Describe the pattern of the perimeters. Use your patternto find the perimeter of the tenth figure in the sequence. (Each small squarehas a perimeter of 4.)a.b.c.2ACTIVITY: Combining FiguresWork with a partner.a. A rancher is constructing a rectangular corral and a trapezoidal corral, asshown. How much fencing does the rancher need to construct both corrals?74 yd70 ydCOMMONCOREGeometryIn this lesson, you will find perimeters ofcomposite figures.Applying Standard7.G.4324Chapter 850 yd74 yd70 yd74 ydb. Another rancher is constructingone corral by combining the twocorrals above, as shown. Does thisrancher need more or less fencing?Explain your reasoning.c. How can the rancher in part (b)combine the two corrals to useeven less fencing?Circles and Area
3ACTIVITY: Submitting a BidWork with a partner. You want to bid on a tiling contract. You will besupplying and installing the brown tile that borders the swimming pool.In the figure, each grid square represents 1 square foot. Your cost for the tile is 4 per linear foot. It takes about 15 minutes to prepare, install, and clean each foot of tile.a. How many brown tiles do you need for the border?b. Write a bid for how much you will charge to supply and install the tile.Include what you want to charge as an hourly wage. Estimate what youthink your profit will be.MathPracticeCommunicatePreciselyWhat do you needto include to createan accurate bid?Explain.4. IN YOUR OWN WORDS How can you find the perimeter of a compositefigure? Use a semicircle, a triangle, and a parallelogram to draw acomposite figure. Label the dimensions. Find the perimeter of the figure.Use what you learned about perimeters of composite figures tocomplete Exercises 3 –5 on page 328.Section 8.2Perimeters of Composite Figures325
8.2LessonLesson TutorialsA composite figure is made up of triangles, squares, rectangles,semicircles, and other two-dimensional figures. Here are two examples.Key Vocabularycomposite figure,p. 326trianglesquaresemicirclerectangleTo find the perimeter of a composite figure, find the distance aroundthe figure.EXAMPLEEstimating a Perimeter Using Grid Paper1Estimate the perimeter of the arrow.Count the number of gridsquare lengths aroundthe arrow. There are 20.Count the number of diagonal lengthsaround the arrow. There are 8.11Length of 20 grid square lengths: 20 1 20 unitsLength of 8 diagonal lengths: 8 1.5 12 unitsSo, the perimeter is about 20 12 32 units.Estimate the perimeter of the figure.Exercises 3–8326Chapter 81.Circles and Area2.Estimate thediagonal lengthto be 1.5 units.
EXAMPLE2Finding a PerimeterThe figure is made up of a semicircle and atriangle. Find the perimeter.The distance around the triangular part of thefigure is 6 8 14 feet.10 ft8 ftThe distance around the semicircle isone-half the circumference of a circle witha diameter of 10 feet.C2πd2— —6 ftDivide the circumference by 2. 3.14 102 —Substitute 3.14 for π and 10 for d. 15.7Simplify.So, the perimeter is about 14 15.7 29.7 feet.EXAMPLE3Finding a PerimeterThe running track is made up of a rectangle and two semicircles.Find the perimeter.The semicircular ends of the track form a circle with a radius of32 meters. Find its circumference.C 2π r32 m 100 mWrite formula for circumference. 2 3.14 32Substitute 3.14 for π and 32 for r. 200.96Multiply.So, the perimeter is about 100 100 200.96 400.96 meters.3. The figure is made up of asemicircle and a triangle.Find the perimeter.4. The figure is made up of asquare and two semicircles.Find the perimeter.8mExercises 9–1126 cm10 cm24 cmSection 8.2Perimeters of Composite Figures327
Exercises8.2Help with Homework1. REASONING Is the perimeter of the composite figure equalto the sum of the perimeters of the individual figures? Explain.2. OPEN-ENDED Draw a composite figure formed by aparallelogram and a trapezoid.6) 39 (- 3) 3 (- 9) 4 (- 1)9 (-Estimate the perimeter of the figure.13.4.5.6.7.8.Find the perimeter of the figure.29.10.5m5m8 in.11 m7m11.15 in.6 cm4 cm8 in.13 in.13 in.9.5 cm4 cm6.5 cm25 in.12. ERROR ANALYSIS Describe and correct the error in finding the perimeterof the figure.4 in.4 in.5 in.5 in.3 in.4 in.328Chapter 8Circles and Area Perimeter 4 3 4 5 4 5 25 in.
Find the perimeter of the figure.13.14.7 in.15.12 in.5 in.5 in.5 in.3 ft3 ft3 ft3 ft3 ft7 in.9 in.5 in.12 ft240 ft 285 ft16. PASTURE A farmer wants to fence a section of landfor a horse pasture. Fencing costs 27 per yard.How much will it cost to fence the pasture?450 ft450 ft40% of a circleof radius 225 ft450 ft225 ft17. BASEBALL You run around the perimeter ofthe baseball field at a rate of 9 feet per second.How long does it take you to run around thebaseball field?300 ft18. TRACK In Example 3, the running track hassix lanes. Explain why the starting points forthe six runners are staggered. Draw a diagramas part of your explanation.19.How can you add a figureto a composite figure without increasingits perimeter? Draw a diagram to supportyour answer.Evaluate the expression. (Skills Review Handbook)20. 2.15(3)221. 4.37(8)222. 3.14(7)223. 8.2(5)224. MULTIPLE CHOICE Which expression is equivalent to (5y 4) 2(7 2y)?(Section 3.2)A y 10 B 9y 18 C 3y 10 Section 8.2D 9y 10 Perimeters of Composite Figures329
326 Chapter 8 Circles and Area 8.2 Lesson A composite fi gure is made up of triangles, squares, rectangles, semicircles, and other two-dimensional fi gures. Here are two examples. square triangle rectangle semicircle To fi nd the perimeter of a composite fi gure, fi nd the distance around the fi gure. Key Vocabulary composite fi gure, p. 326
Mystery . Perimeters. Math Content 3.MD.D.8 . Mystery Perimeters . The Mystery Perimeters lesson is a sample from my complete ebook, Exploring Perimeter. All of the lessons in that book follow the same format with a detailed teacher informat
Types of composite: A) Based on curing mechanism: 1- Chemically activated composite 2- Light activated composite B) Based on size of filler particles: 1 - Conventional composite 2- Small particles composite 3-Micro filled composite 4- Hybrid composite 1- Chemically activated, composite resins: This is two - paste system:
Federal Aviation Administration CE F, General Composite Structure Guidance Background –With the evolving/advancing composite technology and expanding composite applications, AC 20-107 “Composite Aircraft Structure” will require revision Deliverables –Revision to AC 20-107, “Composite Aircraft Structure,” to
Daily Math Practice D Math Buzz 093 Circle prime or composite. 13 prime composite 15 prime composite 22 prime composite 17 prime composite 23 prime composite Multiply. 6 x 728 _ 4 times as many as 397. _ 559 x 9 —–——
Connecting the HDMI to Composite / S-Video Scaler 1. Connect the included HDMI cable from the Hi-Def source to the HDMI connector of the HDMI to Composite / S-Video Scaler. 2. Connect a Composite cable (RCA-type) between the HDMI to Composite / S-Video Scaler and the Composite input on the display or A/V receiver. Optionally connect an
78 composite materials Composite materials resources. Composite Materials Resources scouting literature Chemistry, Engineering, Inventing, Model Design and Building, Robotics, and Space Exploration merit badge pamphlets Books Marshall, Andrew C. Composite Basics, 7th ed. Marshall Consulting Publishing, 2005. Rutan, Burt. Moldless Composite
Composite 3 19 57 37. Prime 38. Prime 39. Neither 40. Neither 41. Composite 11 11 121 42. Composite 3 23 69 43. Prime 44. Prime 45. Composite 3 13 39 46. Composite 7 7 49 47. There are two whole numbers that are neither prime nor composite, 0 and 1. 48. False; the square of a
Zrunners-repeaters-strangers-aliens [ (RRSA) (Parnaby, 1988; Aitken et al., 2003). This model segments inputs of demand from customers (in this case, the requests from researchers for data cleared for publication) and uses the different characteristics of those segments to develop optimal operational responses. Using this framework, we contrast how the rules-based and principles-based .
