Surface area of a frustum of a cone
I can calculate the surface area of a frustum of a cone.
Surface area of a frustum of a cone
I can calculate the surface area of a frustum of a cone.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- The frustum of a cone can be thought of as a cone with the top missing.
- Calculating the surface area for the frustum of a cone is a similar method to finding the area.
- There is an extra face to consider, the top of the frustum.
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.
Common misconception
Pupils may confuse the slant length (which is needed to find the curved surface area of the cone or frustum) with the perpendicular (or vertical) height.
Encourage pupils to clearly label their diagrams, indicating the perpendicular height with a right-angle symbol. They may need to use Pythagoras' theorem or trigonometry to calculate the slant length.
To help you plan your year 11 maths lesson on: Surface area of a frustum of a cone, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 11 maths lesson on: Surface area of a frustum of a cone, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 maths lessons from the 2D and 3D shape: surface area and volume (pyramids, spheres and cones) unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions

a -
16 cm
b -
4 cm
c -
21 cm




Exit quiz
6 Questions




