1. 10.7 Area of Circles and Sectors Brett Solberg AHS ‘11-’12

2. Warm-up

3. Today’s Agenda  pi  Area  circle  activity to discover  sector  segment  Quiz retakes  Test on Tuesday  CRT – 9 classes

4. Pi  ratio of circumference and diameter of a circle  d*π = c  π ≈ 3.1415926525

5. Area of A Circle  What is the radius of:  rectangle  parallelogram  triangle  trapezoid  What do these all have in common?  What is the formula for circumference?  Haw is the radius and diameter related?

6. Area of a Circle A = b*h

7. Area of a Circle  A = π r 2

8. Area Examples  Find the area if:  r = 3  r = 10  d = 14

9. Pizza Sizes

10. 10”12”14”16”23” Area in π Area in decimal

11. Sector  A sector of a circle is a region enclosed by a central angle and an arc.

12. Area of a Sector

13. Example 3  Find the area of a sector with a radius of 6 and a central angle of 100˚.

14. Example 4  Find the area of sector ZOM in terms of π.

15. Segment  Region bounded by an arc and a line connecting the endpoints of the arc.

16. Area of a Segment area of a sector area of an isosceles triangle area of a segment

17. Example 5  Find the area of the shaded segment in terms of π, and then round to the nearest tenth.

18. Example 6  Find the area of the segments and the square. 10 in

19. Assignment  10-7 WS  EC Review pg 592 #1 – 20 all  EC Activity pg 575  Due Next Class  10.1-10.7 Worksheets  Chapter 1-10 Cumulative Review  Warm-ups