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2-dimensional shapes - OCRArea of triangles

2-dimensional shapes are flat. The perimeter of a 2D shape is the total distance around the outside of the shape. The area of a 2D shape is the space inside the shape.

Part of MathsGeometry and measure

Area of triangles

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

Example

Right angle triangle with height = 4cm and width = 2cm
Two 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: \(\text{area of a triangle} = \frac{\text{base} \times \text{height}}{2}\)

In this case:

\(\frac{2 \times 4}{2} = 4~\text{cm}^2\)