Some 3D shapes, like cubes and pyramids, can be opened out and unfolded into a flat shape. The unfolded shape is called the net of the solid.

Here are some 3D shapes and their nets.

Getting nets right

A net has to be able to fold up into the 3D shape. Look at these shapes. All of them are nets of a cuboid. See if you can see why they would fold up into a cuboid.

Getting nets wrong

Look at these shapes. They are not true nets. See if you can see why they wouldn't fold up into a cube.