How do you find the radius with the area of a sector of a circle with a sector which its area is 12pi cm^2 and the angle is 120°?
The radius is 6 cm.
A full circle has 360°, so 120° is 1/3 of the circle. We can use this to find the full area of the circle from which the sector was cut:
Since the full area of the circle is
We ignore the negative value since the radius should be positive.
Since the units of the area are cm^2, the units for the radius are just cm.