Suppose a sector of a circle with radius r has a central angle of 0. Since a sector is a fraction of a full circle, the ratio of a sector’s area A to the circle’s area is equal to the ratio of the central angle to the measure of a rotation of the circle. A full rotation of a circle is 2pi radians. This proportion can be written as A/pi r^2= multiply both sides by pi r^2 and simplify to get Where 0 is the measure of the central angle of the sector and r is the radius of the circle OPTIONS:
0/2pi 0/Pi 0/2pi r A=2pi^2r^2 A=0/pi r^2 A=0r half full