Asector of a circle has an arc measurement of 216 digress. the area of the sector is 15pi cm^2. what is the radius of the circle?

The arc measurement of the sector is 216°.
Therefore the area of the sector is 216/360 = 0.6 of the area of the entire circle.

Let r =  the radius of the circle.
Then the area of the circle is πr².

Therefore the area of the sector is
0.6*πr²

Because the area of the sector is 15π cm², therefore
0.6πr² = 15π
r² = 15/0.6 = 25
r = 5 cm

  5 cm