大象传媒

Calculating the volume of a standard solidVolume of a cone

The volumes of standard 3D solids can be found using specific formulae. In this SQA National 5 Maths revision guide, we'll go through how to work out the volume of a cylinder, sphere, hemisphere, cone, prism, and composite shapes.

Part of MathsGeometric skills

Volume of a cone

The volume of a cone is \(\frac{1}{3}\) of the volume of a cylinder with the same area.

The formula for calculating the volume of a cone, where r is the radius and h is the perpendicular height is:

\(V = \frac{1}{3}\pi {r^2}h\)

Diagram of a cone with labels radius 'r' and height 'h'

Example

Calculate the volume of a cone with radius 5cm and height 12cm.

Answer

\(V = \frac{1}{3}\pi {r^2}h\)

\(= \frac{1}{3} \times \pi \times {5^2} \times 12\)

\(= 314.159...\)

\(= 314.16\,c{m^3}(to\,2\,d.p.)\)

Question

Calculate the volume of a cone with radius 2.7 cm and height 9.2 cm to one decimal place.