Example of a polyhedron with dihedral symmetry and small number of faces

Question

From a comment following this question I see that some polyhedra have dihedral symmetry. I don't understand what the would be like. Rather than getting technical, can you provide a simple example of such a polyhedron?

Answer 1

Prisms and antiprisms already have dihedral symmetry plus an additional reflection symmetry. If you want only dihedral symmetry and nothing else, you can take a prism and cut each vertical rectangular face along a southwest-to-northeast diagonal, so that you have two triangles instead. This removes the reflectional symmetry of the prism, but preserves the rotational and flip symmetries.

(If you want the faces to be non-degenerate, just push each triangle out into a pyramid by adding a vertex in the center.)