Area of triangles

To calculate the area of a triangle, draw a second triangle to form a rectangle.


Right angle triangle with height = 4cm and width = 2cmTwo right angle triangles forming a rectangle

The area of the rectangle is 8 cm2.

Two triangles make the rectangle. The area of one triangle is half the area of the rectangle.

\[8 \div 2 = 4~\text{cm}^2\]

The area of a triangle can also be calculated using the formula:

\[\text{area of a triangle} = \frac{1}{2} \text{base} \times \text{height}\]


\[\text{area of a triangle} = \frac{\text{base} \times \text{height}}{2}\]

In this case:

\[\frac{2 \times 4}{2} = 4~\text{cm}^2\]