You often need to use Pythagoras' theorem more than once in each problem as we create extra right-angled triangles in the 3D shapes. Example This cuboid has side lengths of 2cm, 3cm and 6cm.

Surface area is the sum of the area of each face. 3D shapes can be viewed from different points. ... Pythagoras’ theorem can be applied to solve 3-dimensional problems. Units of measure - Edexcel.

This theorem provides a reliable method for calculating unknown side lengths when working with these specific geometric shapes. The mathematical expression appears as: a² + b² = c² ...