Frustum - GCSE Maths Definition

In geometry, a frustum is a shape that you get when you cut the top off a cone or a pyramid with a flat, parallel cut. Imagine you have an ice cream cone and you slice the pointy bottom part off in a way that leaves it flat. The remaining shape with two parallel circular ends is called a frustum. A frustum can also be part of a pyramid, where you cut it horizontally and end up with one part that looks like a flat-topped pyramid. In maths, you might have to calculate the volume or surface area of a frustum, which involves working out the area of the flat surfaces and any surfaces in between.