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What is area?

Year 4 finds area by counting squares, Year 5 calculates the area of rectangles, and Year 6 the area of triangles and parallelograms. Below: what it means, a worked example, the mistake to watch for and an 11+ question.

The answer

Area is the amount of flat space inside a shape, measured in squares, such as square centimetres (cm²).

What it means

For a rectangle, multiply the length by the width. A 6 cm by 4 cm rectangle has an area of 24 cm²: 24 squares, each 1 cm by 1 cm.

A triangle has half the area of the rectangle around it: ½ × base × height. A parallelogram has base × perpendicular height.

A worked example

Find the area of a rectangle 9 m long and 3 m wide

  1. Area = length × width.
  2. 9 × 3 = 27, so the area is 27 m².

The common mistake

Writing the answer in cm instead of cm². Area counts squares, so its unit is always squared.

How it comes up in the 11+

An L-shape is made by cutting a 4 cm by 3 cm rectangle from one corner of a 9 cm by 6 cm rectangle. What is the area of the L-shape?

Answer: 42 cm²

  1. The big rectangle is 9 × 6 = 54 cm².
  2. The piece cut out is 4 × 3 = 12 cm².
  3. 54 − 12 = 42 cm².

Try it yourself

It opens on the L-shape from the 11+ question: a 9 by 6 rectangle with a 4 by 3 corner cut out. Count the squares, then tap to change it.

Draw a shape on squared paper to see its area, the squares inside, and its perimeter, the edges round the outside.

Related words and practice

More maths words

Questions parents ask

What is the difference between area and perimeter?

Area is the space inside a shape, counted in squares. Perimeter is the distance round the edge, measured in lengths.

How do you find the area of a triangle?

Multiply the base by the height and halve it. A triangle with a base of 8 cm and a height of 5 cm has an area of 20 cm².

Knowing the words is half of an 11+ maths question

11+ papers use maths vocabulary without explaining it. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.