The area of each square is 1 cm 2. There are 12 squares contained in this rectangle. The area of the rectangle is 12 cm 2. The area of a rectangle can also be calculated using the following formula.

The green rectangle B has been enlarged by a scale factor of 3 and now has a width of 9cm and a length of 12cm. Let’s work out the original dimensions of the purple rectangle A. To work out its ...