1. 10-7 Areas of Circles and Sectors Objective To find the areas of circles, sectors, and segments of circles

2. What is… 12 a) db) rc) 2rd) r 2

3. Theorem 10-11 Area of a Circle

4. What is the area of a circle with 15 cm radius?

5. Ex. 1 How much more pizza is in a 12 in. than a 10 in pizza Find the areas of each and subtract

6. Sector of a circle TThe region bounded by 2 radii and their intercepted arc EEx would be a slice of pizza SSectors are named by using one endpoint of the arc, the center, and the other endpoint

7. Theorem 10-12 Area of a sector of a circle TThe area of a sector of a circle is the product of the ratio (measure of arc/360) and the area of the circle.

8. Ex. 2 Z O M 72° r = 5 in

9. Ex. 3 CCircle has a d = 20 cm. What is the area of a sector bounded by 208° arc? Round to the nearest tenth.

10. Segment of a circle Part of a circle bounded by an arc and the segment connecting its endpoints

11. To find the area of a segment 1 st draw in the radii to form a sector. 2 nd find the area of the sector 3 rd find the area of the triangle 4 th subtract (sector-triangle)

12. Ex. 4 A O B 10 in

13. Ex. 5 radius is 12cm and 60° arc. Find the area of the segment 60° 12

14. CLASSWORK Pages 663-664 7-18 (all) 23-31 (all) 38