POOLS The diagram of the pool from the beginning of the lesson is shown below. Find the area of the pool s floor. 28 ft. 6 ft. 4 ft.

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1 Multi-Part Lesson 9-3 PART Main Idea Find areas of composite figures. glencoe.com Composite Figures A C B D Area of Composite Figures 8 ft POOLS The dimensions of a pool at recreation center are shown.. Describe shape of pool. See margin. ft. How could you determine area of $ "@/"@ " pool s floor? Separate shape into a rectangle and a trapezoid, find area of each, and add to find total area. To find area of a composite figure, separate it into figures with areas you know how to find. Then add those areas. Find Area of a Composite Figure Find area of figure at right. The figure can be separated into a rectangle and a triangle. Find area of each. Area of Rectangle 0 in. Area of Triangle 0 in. $ $ " ART FILE: C-4A_NA_ A=_ bh A = bh A = 0 6 or 60 C09-0A Glencoe CUSTOMER: Altered The base of BY: triangle is MF A = _(4)(4) or or 4 inches. C09-A CS EDITED BY: simple only altered@ 3 greyscale.5 cm ft.5 cm 9. cm 3. Lesson 9-3 Composite Figures $ $ " $ $ # 4 (p complex b. 8 ft 59_53_SE.indd 59 mod. blackline Find area of each figure. 0 ft created@ NETS REVISION: 60 ft 9-9- TIME: 8 m The area is or 68 square inches. a. JOB NUMBER 59 7/9/09 4:4:7 PM c

2 POOLS The diagram of pool from beginning of lesson is shown below. Find area of pool s floor. 8 ft ft The figure can be separated into a rectangle and a trapezoid. $ "@/"@ " The area of rectangle is 8 4 or 39 square feet. The area of trapezoid is _ ()(4 + 6) or 0 square feet. So, area of pool s floor is or 40 square feet. Real-World Link The largest swimming pool in world is located in Chile. It is one kilometer in length and is equivalent to approximately 6,000 standard pools. Find area of figure at right. The figure can be separated into a square and a rectangle. The shared rectangle, however, will be counted twice if areas are added, so area of small rectangle, 6 7 or 4, must be subtracted from total. cm 6 cm 8 cm cm cm 5 cm The area of square is or 44 square centimeters. The area of rectangle is 5 or 80 square centimeters. C09-03A ART FILE: C-4A_NA_ The sum of areas is or 34 square centimeters. Glencoe CUSTOMER: TECH JOB NUMBER: Since small rectangle was counted subtract its area Altered BY:twice,MF CS from total = 8 EDITED BY: So, area of figure is 8 square centimeters. c. DECKS Find area of deck shown. 67 ft only altered@ NETS simple mod. blackline 3 4 complex greyscale d. Find area of figure below. 65 ft 0 ft TIME: 8 m created@ NETS REVISION: 0555 (place checkmark) ( 4&.4.B OE QBTT -,FMM v. complex color ft 7 ft 0 ft 0 ft 3 8 ft ft C-8A A 50 Chapter 9 Use Formulas in Geometry C09-04A _53_SE.indd 50 7/9/09 4:4:8 PM

3 Example (p. 59) Find area of each figure. Round to nearest tenth if necessary.. m. 04. ft 3. m 4 m 7 m 4 m 5 ft 4 m 5 m 4 m 0 m 0 m 45 m Examples and 3 (p. 50) 4. APARTMENTS The manager of an apartment complex will install new carpeting in a studio apartment. The floor plan is shown at right. What is total area that needs to be carpeted? 34.5 ft 5. TILING The floor plan of a kitchen is shown at right. If entire kitchen floor is to be tiled, how many square feet of tile are needed? 88 ft ft 8 ft 5 ft C-5C A 0 ft 5 ft ft ft ft = Step-by-Step Solutions begin on page R. Extra Practice begins on page EP. C-33C B Example (p. 59) Find area of each figure. Round to nearest tenth if necessary cm in yd 9. 7 cm 8 in. 5 yd 0 cm 87.5 cm 8 in in 7 yd 0 mm 5. yd. 0 mm 57. mm ft 66. yd 8 ft 4. 7 yd 4 yd yd 5. yd Examples and 3 (p. 50). BLUEPRINTS On a blueprint, a rectangular room 4 feet by feet has a semicircular sitting area attached with a diameter of feet. What is ft total area of room and sitting area? about 4.5 ft 3. POOLS The diagram at right gives 8 ft dimensions of a swimming pool. If a cover is needed for pool, what will be 0 ft approximate area of cover? Lesson 9-3 Composite Figures 5 C-067A B 59_53_SE.indd 5 7/9/09 4:4:3 PM

4 4. GRAPHIC NOVEL Refer to graphic novel frame below for Exercises a b. Let s just find area of larger circle and take out area of smaller circle! a. Find area of dirt bike track. Use 3.4 for π. 3,06.5 ft b. Suppose it costs $4.99 to cover one square foot of dirt bike track with dirt. How much will it cost to cover track with dirt? Round to nearest cent. $5,76.89 B 5 PAINTING The diagram shows one side of a storage barn. a. This side needs to be painted. Find total area to be painted b. Each gallon of paint costs $0 and covers 350 square feet. Find total cost to paint this side once. Justify your answer. See margin. 6.5 ft 4.5 ft.8 ft $ " " CHALLENGE Describe how to separate each state into simpler figures. Then use se figures to estimate area of each state. One square unit equals,400 square miles. Justify your answer. 6. Sample answer: Add areas of a rectangle and a triangle. Area of rectangle: 3 4 = ; Area of triangle: _ 3 3 = 4.5; 6. See margin. 7. NEVADA = 6.5. So, an approximate area 8. C-5A_NA_ A Describe how you would find 9 cm is 6.5,400 or area of figure shown at right. Sample 39,600 mi. 5 cm answer: Separate it into a rectangle and a triangle, $ " find area of each, and add. 7 cm 5 Chapter 9 Use Formulas in Geometry $ $ " 59_53_SE.indd 5 7/9/09 4:4:35 PM

5 Practice 9. What is area of window shown? Use 3.4 for π. A 0. The shaded part of grid represents plans for a fish pond in. A.,36.68 in C in H. 50 square feet B.,78 in D. 68 in I. 33 square feet. EXTENDED RESPONSE To promote recycling, ground of neighborhood playground shown is being covered by shredded tires. The sandbox will not be covered. Part A What is area, in square feet, of shredded tire portion of playground? 3,50 ft Part B If shredded tires cost $.99 per square foot, at required depth, how much will it cost to cover playground? $9,48.50 If each square on grid represents 5 square feet, what is approximate area of fish pond? G F. 75 square feet G. 65 square feet sandbox 30 ft 80 ft 5 ft 45 ft Find perimeter of each figure. (Lesson 9-3A). 5.8 in ft cm 8 cm 9. cm.6 cm Find area of each circle. Use 3.4 for π. Round to nearest tenth. C09-07A (Lesson 9-D) C09-08A C09-09A radius = 4.7 cm radius = in. 45. in 7. diameter = 5 in in Lesson 9-3 Composite Figures 53 59_53_SE.indd 53 7/9/09 4:4:38 PM