The triangle is right-angled, with the right angle in the lower left corner of the shape. It has a base of labelled as four centimetres and height labelled as three centimetres.

Triangles, squares, rectangles and pentagons are examples of polygons. A polyhedron is a 3D shape with faces made from polygons. Cubes, cuboids, tetrahedron and prisms are examples of polyhedra.