## Nets and surface area

The *net* of a 3D shape is the flat shape you would get if you unfolded the shape. For example, here is a 3D cube
and the net (which consists of 6 flat squares):

Once you have found the net of a 3D shape, you can calculate the surface area by calculating the areas of each shape in the net, and adding them together.

In the examples in this section, there are various animated 3D shapes that you can fold and unfold interactively.