Consider the right prism as shown in the figure. There are as many cubic units in each layer parallel to the base as there are square units in the area of the base. Also, there are many layers of cubic units in the prism as there are linear units in the altitudes . We can, therefore, find the total number of cubic units in the prism by multiplying the area of the base by the altitude.

Volume of the Prism Area of the Base Height of the prism

**Rule: **The volume of the prism equals its base times its altitude.

__Example__:

The base of a right prism is an equilateral triangle with a side of cm and its heights is cm, find its volume.

__Solution__:

Volume

Since, base is an equilateral triangle

cm

cm

Cubic cm

__Example__:

The sides of a triangular prism are cm, cm and cm respectively. The volume of the prism is cubic cm. What is its height?

__Solution__:

Now,

Square cm