Question

A triangular prism has a height of 12 cm. The triangular base is a right triangle whose side lengths are 3 cm, 4 cm, and 5 cm. What is the total surface area?

Answer 1

The volume of the prism is 72 cubic cm.

Explanation:

This we know because a triangle with sides of 3 units, 4 units, and 5 units must be a 3–4–5 right triangle, the catheti (“legs”) of which are 3 and 4 units. So the area of the base is

3 cm. * 4 cm. / 2 = 6 square cm.

Lastly, the volume of the prism is the base area multiplied by the height:

6 square cm. * 12 cm. = 72 cubic cm.