Net of a cube side 3

Step by step

The question

Question: draw the net of a cube, side 3, and find its surface area.

The surface area is the area of all the outside faces together.

A net shows every face flat.

1 Unfold it

We cut along some edges and fold it flat.

Matching faces have the same colour.

2 Area of each face

Top and bottom: 3 × 3 is 9.

Front and back: 3 × 3 is 9.

The two sides: 3 × 3 is 9.

Careful!

Count every face in the net.

A box has 6 faces, not 3.

3 Add them all

We add all 6 faces: 54.

4 Check

Let's check another way.

All 6 faces of a cube are the same square: 6 times 9 is 54.

So the answer is right!

Let's look back.

First: unfold it.

Then: area of each face.

Then: add them all.

Last: check.