Pre-Algebra Practice Questions: Finding the Volume of Pyramids and Cones

The formula for the volume of a pyramid is the same as for the volume of a cone. In this formula, A_b is the area of the base, and h is the height:

Practice questions

1. Find the volume of a pyramid with a square base whose side is 10 inches and with a height of 6 inches.
2. Find the approximate volume of a cone whose base has a radius of 3 inches and whose height is 8 inches.

Answers and explanations

1. 200 cubic inches

   First, find the area of the base using the formula for the area of a square:

   A_b = s² = (10 in.)² = 100 in.²

   Now plug this result into the formula for the volume of a pyramid:

   

2. Approximately 75.36 cubic inches

   Use the area formula for a circle to find the area of the base:

   

   Plug this result into the formula for the volume of a cone: