Substitute the base and height values into the formula. (9 × 12) ÷ 2 = 54 The area of the triangle is 54 mm² Working in centimetres the base is 0∙9 cm, and the height is 1.2 cm. Substitute ...

You may choose any of the triangles as they are all the same area in a rectangle. The area of the shaded triangle can be worked out as either \( \frac{1}{4}\,\,\times16.3\,\times\,12.4 = 50.53\,m^{2} ...