# Area of 2D shapes

The amount of flat space inside a shape, measured in square units.

Maths (school) · Part 05: Angles and area · Card 4 of 8 · Last updated 2026-10-19

## Analogy

Like counting how many square tiles it takes to cover a floor.

## Example

**Trapezium area**

Formula: 1/2 x (a + b) x h
a = 6, b = 10, h = 4
= 1/2 x 16 x 4 = 32 square units

## In practice

Painters work out wall areas to know how many tins of paint to buy.

## Practice

### Flashcards

- **What is the area of a trapezium with parallel sides 6 and 10, height 4?** 32. Use 1/2 x (6 + 10) x 4.

## Questions people ask

### What is the area of a triangle?

Half the base times the perpendicular height: area = 1/2 x b x h. The height must be measured at a right angle to the base, not along a slanted side. A triangle with base 8 and height 5 has area 1/2 x 8 x 5 = 20.

### Why are areas measured in square units?

Area counts how many squares of a standard size fit inside a shape. So the units are squared: square centimetres (cm^2) or square metres (m^2). A room 4 m by 3 m has an area of 12 m^2, not 12 m.

Web page: https://studyvisually.com/learn/science/maths-school/maths-school-part-5/maths-school-part-5-concept-4
Study this card in the app: https://studyvisually.com/app/learn?category=maths-school&card=maths-school-part-5-concept-4