Section 11-5 Areas of Circles and Sectors
Area of a Circle The area of a circle is times the square of the radius. Formula:
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!
Slices of Pizza are Sectors!
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.
In General: Area of a sector =
Example: 5 Find the area of sector AOB. units units 2 3.