A solid consists of a cone on top of a cylinder with a radius equal to that of the cone. The height of the cone is 18 18 and the height of the cylinder is 21 21. If the volume of the solid is 420 pi420π, what is the area of the base of the cylinder?

1 Answer
Jan 12, 2017

The area is =48.9u^2=48.9u2

Explanation:

The volume of the cylinder == area of base * height

The volume of the cone =1/3*=13 area of base * height

Let a=a= area of the base

Volume of the cone =1/3*a*18=6a=13a18=6a

Volume of cylinder =a*21=21a=a21=21a

Total =6a+21a=27a=420pi=6a+21a=27a=420π

a=420/27pi=48.9 u^2a=42027π=48.9u2