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What is a cube?

A cube is a 3D shape with six square faces that are all the same size.

The answer

A cube has 6 faces, 12 edges and 8 vertices.

Cube diagram and properties

Dashed lines are edges hidden round the back.
PropertyCount
Faces6 identical squares6
Flat faces6
Curved faces0
Edges12
Vertices (corners)8

Key facts about the cube

  • Three faces meet at every vertex, and every edge is the same length.
  • A cube is a special cuboid, and a special square-based prism.
  • There are 11 different nets that fold up into a cube.
  • Volume = length × length × length. That is where "cubed" and cube numbers get their name.

Where you see it

A dice, a sugar cube, a Rubik's cube and a building block.

The common mistake

Counting 4 or 5 faces from a drawing. Some faces are hidden round the back: a cube always has 6, which is why the dashed lines matter.

An 11+ style question

A cube has edges 3 cm long. What is its volume?

Answer: 27 cm³

  1. Volume of a cube = length × length × length.
  2. 3 × 3 × 3 = 27, so the volume is 27 cm³.

Which nets fold into a cube?

Try arrangements of six squares and see which ones fold up into a cube.

Six squares joined edge to edge make a cube net only if they fold without overlapping. There are 11 different cube nets.

Related shapes and skills

More shapes

Questions parents ask

How many faces, edges and vertices does a cube have?

A cube has 6 faces, 12 edges and 8 vertices. In 11+ nets questions, a row of 4 squares with 1 square above it and 1 below it always folds into a cube, wherever along the row those two squares sit.

How many nets does a cube have?

There are 11 different nets of a cube. Each is 6 squares joined edge to edge. The widget on this page lets you test which arrangements fold up.

Shape questions are quick marks in the 11+

Angles, symmetry, nets and 3D shapes come up in 11+ maths and non-verbal reasoning. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.