# Explain how to calculate the area of a triangle

I can explain how to calculate the area of a triangle.

# Explain how to calculate the area of a triangle

I can explain how to calculate the area of a triangle.

## Lesson details

### Key learning points

- The area of a triangle is half the area of a parallelogram with same base and perpendicular height.
- The area of a triangle can be calculated using the formula area = base × perpendicular height ÷ 2

### Common misconception

Pupils often over-generalise the word 'base' and do not recognise that the base is not always horizontal or the 'bottom' part of the shape.

Take time to identify that the base is related to the perpendicular height and show that one triangle can have a different base dependent on where the measurement is taken from. Pupils should consider efficiency when selecting a base.

### Keywords

Parallelogram - A parallelogram is a quadrilateral with two pairs of parallel and equal sides.

Base - The base is the side which is perpendicular to the shape’s height.

Perpendicular - Two lines are perpendicular if they meet at a right angle.

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Video

Loading...