### Using volume to calculate side length for a rectangular prism

If we know the volume and two of the side lengths for a rectangular prism, we can calculate the third length. We divide the volume by the product of the two known side lengths.

#### Example 1

A rectangular prism has volume 56 m^{3}, length 2 m and width 4 m. What is its height?

#### Solution

\begin{align}\text{Volume}&=\text{length}\ ×\ \text{width}\ ×\ \text{height}\\\\ \text{So, Height}&=\dfrac{\text{volume}}{\text{length}\ ×\ \text{width}}\\\\ &=\dfrac{56}{2×4}\\\\ &=\dfrac{56}{8}\\\\ &=7\ \text{m}\end{align}The height of a rectangular prism with volume 56 m^{3}, length 2 m and width 4 m is 7 m.

### Summary

The volume of a rectangular box in cubic centimetres is the number of 1 cm × 1 cm × 1 cm cubes that fit inside it.

The formula for calculating the volume of a rectangular prism is:

Volume = length × width × height