1. Section 11-5 Areas of Circles and Sectors

2. Area of a Circle The area of a circle is times the square of the radius. Formula:

3. Sector of a circle A region bounded by two radii of the circle and their intercepted arc. A B O C Sector AOB *The unshaded region is also a sector!

4. Slices of Pizza are Sectors!

5. To find the area of a sector: 1.Find the Area of the Circle 2.Find the ratio of the measure of the arc to the whole circle. 3.Find the product of the ratio and Area.

6. In General: Area of a sector =

7. Example: 5 Find the area of sector AOB. units 2 1. 2. units 2 3.