in a circle, a 180° sector has area 72π in2.
What is the radius of the circle?
Solve...
Area of a sector = pi * radius^2 * (central angle measure of the sector / 360) ....so we have..
72 pi = pi (r^2) (180/ 360) divide out pi
72 = (1/2) r^2 multiply both sides by 2
144 = r^2 take the positive root
12 in = r
