Key learning points

1. The frustum of a cone can be thought of as a cone with the top missing.
2. Calculating the surface area for the frustum of a cone is a similar method to finding the area.
3. There is an extra face to consider, the top of the frustum.

Common misconception

Keywords

• Frustum - A frustum is the 3D shape made from a cone by making a cut parallel to its circular base and removing the resultant smaller cone.

• Surface area - The surface area is the total area of all the surfaces of a closed 3D shape. The surfaces include all faces and any curved surfaces.