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 ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. 00:00:00:00 ED LEMBKE-HOGAN: Did you know that there are 138 known pyramids in Egypt, all of them ...