3D Shape – Features of Prisms and Pyramids . Identifying and defining different 3D shapes can by quite complex and the geometric terms used in many definitions can be difficult to comprehend and to explain e.g. congruent, parallel, lateral, apex. . Students need to be able to identify the difference between 3D shapes and 2D shapes and identify that 3D shapes have 2D shapes (polygons) as their faces. The two most common groups of 3D shapes are prisms and pyramids. . Prisms are shapes that have tw