The volume of the cone is 9π, and its height is 3. Find the radius of the base of the cone.

The volume of the cone is found by the formula:
V = SH / 3,
where S is the area of the base, H is the height of the cone.
Find the area of the base of the cone:
3 * S / 3 = 9π;
S = 9π (conventional square units).
There is a circle at the base of the cone. Then 9π is the area of a circle.
The area of a circle is found by the formula:
S = πR ^ 2,
where R is the radius of the circle.
Then:
πR ^ 2 = 9π;
R ^ 2 = 9π / π;
R ^ 2 = 9;
R = √9;
R = 3 conventional square units.
Answer: R = 3 conventional square units.