In this activity, we will calculate the surface area of 3D shapes
The surface area of a 3D shape is the area of all the faces of the shape added together.
It is easy if we imagine the net of the shape.
Remember, the net of a 3D shape is what the shape would look like if it was opened out and laid flat.
The net of a cube looks like this.......
It is made up of six identical square faces.
If each side of the square face was 2 cm we could work out the surface area of the cube.
The area of one side is base x height = 2 x 2 = 4 cm2
There are six identical sides
Surface area = 6 x 4 cm2
= 24 cm2
Let's try some questions with some other 3D shapes!