Volume of a Prism

Volume of a Prism


A prism is a 3D solid. It has the same cross-section along its entire length: if the prism is cut at right angles to its length at any point, then it has the same face on the cut sections as it does at each end.

The area of a prism is:

Volume = cross-sectional area x length


1. The cross-sectional area of a prism is 20 cm2. The length of the prism is 5cm. What is the volume of the prism?

Answer: 100cm3

The volume of a prism is cross-sectional area x length

V = 20 x 5 = 100

2. A prism with a complex cross-sectional are is 15cm long. The volume of the prism is 345cm3. What is the cross-sectional area of the prism?

Answer: 23cm2

Volume = Area x length

345 = Area x 15

Area = 23