Answer: r = 4
Step-by-step explanation:
V = pi * r^2 * h
144 * pi = pi * r^2 * 9
Divide by pi
144 = r^2 * 9
Divide by 9
16 = r^2
Take square root of both sides
rad(16) = rad(r^2)
4 = r
r = 4
