Understanding 3D shapes for 11+ maths
21 October 2026
Why 3D shapes matter in 11+ maths
Understanding 3D shapes is a key skill for the 11+ maths exam. Children need to recognise and describe the properties of these shapes, including faces, edges and vertices. This helps with questions on shape sorting, nets and reasoning.
Faces, edges and vertices explained
A face is a flat or curved surface on a 3D shape. An edge is where two faces meet. A vertex (plural: vertices) is a corner where edges meet. These three properties help us describe and compare 3D shapes.
Common 3D shapes and their properties
A cube has 6 faces, 12 edges and 8 vertices. A square-based pyramid has 5 faces, 8 edges and 5 vertices. A cylinder has 3 faces (2 flat, 1 curved), 2 edges and no vertices. These examples often appear in 11+ questions.
Worked example: describing a cube
Let's find the number of faces, edges and vertices in a cube step by step.
First, count the faces. A cube has 6 square faces.
Next, count the edges. Each face has 4 edges, but edges are shared, so 6 × 4 = 24, then 24 ÷ 2 = 12 edges.
Now, count the vertices. Each corner is where 3 edges meet. There are 8 vertices in total.
The correct answer is: a cube has 6 faces, 12 edges and 8 vertices.
Summary and key insight
Knowing how to describe 3D shapes using faces, edges and vertices gives children a strong foundation for 11+ maths. This skill makes it easier to tackle shape questions and builds confidence in geometry.
Key insight: Mastering the properties of 3D shapes is essential for success with 11+ maths shape and reasoning questions.
