The perpendicular height is 4 cm. Substitute the base and perpendicular height values into the formula. (7 × 4) ÷ 2 = 28 ÷ 2 = 14. The area of the triangle is therefore 14 cm² ...

For triangles that are not right-angled, the base is one of the sides and the perpendicular height may be shown either inside or outside the shape, it is not another side.