Volume

In this section of Revision Maths you will learn how to calculate the volume of prisms, pyramids and frustums.

Volume is a 3D Measurement so we need to always write answers as cubed numbers, for example CM³ or M³.

Volume of a Prism

To calculate the volume of a prism you need to use this formula: Area of a cross-section x height or length.

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In the example above the volume = 4 x 5 x8 = 160cm³

To find out how to work out the area of a 2D shape click here.

Volume of a Pyramid

To calculate the volume of a pyramid you use this formula: 1/3 area of a cross section x height.

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In the example above the volume = 1/3 x 4 x 5 x 8 = 53.33cm³ (to 4.s.f).

Volume of a Frustum

A frustum is made by cutting the top end of a cone to calculate the volume of a frustum use the formula below:

 1/3 π R² H – 1/3 πr²h

The second half of the formula is how to work out the volume of the entire cone.

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In the example above 1/3π [(8² x 11) – (4² x 5)

So the volume of this frustum = 208 πcm³ or 653cm³ (to 3 s.f)