In a rectangle we can still find the area by counting squares, but we can also multiply the two lengths together.
We can see that the area is 10 cm² by counting squares, but if we multiply the lengths:
We have to be careful to use the same units when doing calculations.
A square which is 1cm × 1cm has area 1cm².
The same square is 10mm × 10mm, and 10×10=100, so its area is 100 mm².
Similarly, a square which is 1m × 1m has area 1m².
The same square is 100cm × 100cm, and 100×100=10000, so its area is 10000 cm².
Be careful to remember these facts whenever you are converting the units of an area.
Do each of these questions then click on the button marked to see whether you are correct.
The rectangle measures 3cm × 4cm so the area is 12 cm².
Find the areas (in cm²) and perimeters (in cm) of the rectangles below.
The squares on each grid are 1cm × 1cm.
Find the areas and perimeters of the rectangles below.
The diagrams have not been drawn accurately.
Look at the rectangle below.
Find the area of this rectangle in mm² and cm².
A rectangle has an area of 48 cm². The length of one side is 6 cm.
A rectangle has a perimeter of 24 cm and an area of 32 cm².