The volume of clay used to build a cylindrical pillar with a height of 9 centimeters is 324π cubic centimeters. The area of the base of the pillar is ____ π square centimeters.

Answer 1

Hello, Sarah,

The volume of a cylinder is V=πa²h, where a is the radius, and h is the height.

The area of the base is A=πa²

We know the height, 9cm, and the volume, 324π cm3

Lets enter what we know in the first equation:

324π cm3 ⁼ πa²(9cm)

The π's conveniently cancel, leaving 324cm³ = (9cm)a²

a² = 36cm²

a = 6cm

Since the radius, a, is 6cm, the area of the base is

A=πa²

A = (3.14)(6cm)²

A = 113.1 cm², but we want to answer in units of π. So it would be 36π cm²

Bob