The other triangles are irregular polygons. 3D shapes have different properties to 2D shapes. Faces - A face is a flat surface on a 3D shape. Edges - An edge is where two faces meet. For example a ...

A 2D shape could have line symmetry or rotation symmetry, or both! 3D shapes are described by their faces, edges and vertices. The faces can be the same shape or different, and a 3D shape could ...