Find the volume of the sphere.

The formula for the volume of a sphere is V = (4/3)πr^3, where r is the radius.

Substituting r = 9 into the formula, we get:
V = (4/3)π(9^3)
V = (4/3)π(729)
V = (4/3) * 729 * π
V = 972π

Therefore, the volume of the sphere is 972π cubic units.