There are many types of nets for the different 3D shapes. A net is made from polygons that can be folded and joined to make a polyhedron. Here is the net of a triangular prism. Why not see how ...

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 ...