First, find the height of the cone. Use the Pyth. Thm. for this calculation:
15^2 + h^2 = 25^2, or 225 + h^2 = 625. Then h^2 = 400 and h = + 20 units.
The voume formula applicable here is
V = (1/3)(base)(height).
Specifically,
V = (1/3) π(225)(20) units^3
= 1500*pi units^3
