Cubes and cuboids

Cubes

A cube is a solid three dimensional shape which has 6 square faces, 8 vertices and 12 edges. Look at the picture below. It will help you understand what a vertex, an edge and a face of a cube are.

If you cut open a cube along its edges, you would end up with something that looks like one of the diagrams in the picture below. These are known as the nets of a cube. Look at each one carefully. Notice that they all show the six square faces which make up the cube.

Image by BergerGießen and used under this creative commons license

Some objects that we see around us are shaped like cubes. Look at the pictures below.

This toy is called a rubik’s cube. It is also shaped like a cube.

Cuboids

A cuboid is a three dimensional shape with 6 rectangular faces, 8 vertices and twelve edges. The definition for a cuboid is very similar to the definition for a cube. The difference is that the faces of a cube must be squares but the faces of a cuboid are rectangles. Look at the picture below.

Can you see the faces, vertices and edges of the cuboid?

The nets of a cuboid look similar to the nets of a cube. However the net of a cuboid would be made up of rectangles. A net of a cuboid below. If you cut open a cuboid along its edges, this is what you may see. Notice it is made up of six rectangles.

Many items that we see around us are shaped like cuboids. Look at the pictures below.

Cardboard boxes are often shaped like cuboids.

Some buildings are made of bricks. Bricks are often shaped like cuboids. (Image by Mtpanchal and used under this creative commons license)

Note: Since all squares are also rectangles, all cubes are also cuboids. However, all cuboids are not cubes.