1. Over Lesson 11–8 A.A B.B C.C D.D 5-Minute Check 1 Find the area of a circle to the nearest tenth. Rebecca cuts a round piece of cardboard to use to make a top hat. The diameter is 7.5 centimeters. What is the area of the cardboard circle?

2. Splash Screen

3. Then/Now You found the areas of parallelograms, triangles, and trapezoids. (Lesson 11–6) Find the area of composite figures. Solve problems involving the area of composite figures.

4. Concept

5. Vocabulary composite figure A figure that is made up of two or more shapes

6. Example 1 Find the Area of Composite Figures Find the area of the composite figure. Round to the nearest tenth if necessary. First, separate the figure into a triangle, square, and a quarter-circle. Then find the sum of the areas of the figure.

7. Example 1 Find the Area of Composite Figures b = 2 and h = 4 Simplify. Area of a triangle

8. Example 1 Find the Area of Composite Figures A=s 2 Area of a square A=2 2 s = 2 A=4Simplify.

9. Example 1 Find the Area of Composite Figures r = 2 Simplify. Area of a quarter-circle

10. Example 1 Find the Area of Composite Figures Answer: The area is about 11.1 square inches. Total Area A = 4 + 4 + 3.1Add the areas A = 11.1 in 2 Simplify

11. A.A B.B C.C D.D Example 1 A.71.1 cm 2 B.58.6 cm 2 C.58.3 cm 2 D.52.3 cm 2 Find the area of the figure to the nearest tenth.

12. Example 2 Solve Multi-Step Problems CARPETING Carpeting costs $2 per square foot. How much will it cost to carpet the area shown? UnderstandYou know the dimensions of the figure. You need to find its area. PlanFirst, separate the figure into a rectangle, a square, and a triangle. Then find the sum of the areas of the figure.

13. Example 2 Solve Multi-Step Problems Step 1Find the area to be carpeted. Area of Rectangle A=bhArea of a rectangle A=(14)(10)Replace b with 14 and h with 10. A=140Simplify. Solve

14. Example 2 Solve Multi-Step Problems Area of Square A=s 2 Area of a square A=3 2 Replace s with 3. A=9Simplify. Solve

15. Example 2 Solve Multi-Step Problems Area of Triangle The area to be carpeted is140 + 9 + 84 or 233 square feet. Replace b with 14 and h with 12. Simplify. Area of a triangle Solve

16. Example 2 Solve Multi-Step Problems Answer: So, it will cost $466 to carpet the area shown. Step 2Find the cost of the carpeting. 2(233) = 466 CheckThe area of the figure should be a little less than the area of a rectangle that is 14 feet by 22 feet. Since the area of a 14-by-22-foot rectangle is 308 square feet, the answer of an area of 233 square feet is reasonable.

17. A.A B.B C.C D.D A.about 3 gallons B.about 4 gallons C.about 5 gallons D.about 6 gallons Example 2 PAINTING One gallon of paint is advertised to cover 100 square feet of wall surface. About how many gallons will be needed to paint the wall shown?

18. End of the Lesson