A 3D shape with all straight edges and flat faces is a polyhedron. Other 3D shapes with least one curved surface are not polyhedra. A 3D shape with regular polygonal faces, meeting at equal angles, is ...

Pythagoras' theorem can also be used to solve 3D problems. You often need to use Pythagoras' theorem more than once in each problem as we create extra right-angled triangles in the 3D shapes. First ...