'Given the faces of the polyhedra we can get the edges.
Examples
>>> from sympy.combinatorics import Polyhedron
>>> from sympy.abc import a, b, c
>>> corners = (a, b, c)
>>> faces = [(0, 1, 2)]
>>> Polyhedron(corners, faces).edges
{(0, 1), (0, 2), (1, 2)}'

@property
def edges(self):

    if (self._edges is None):
        output = set()
        for face in self.faces:
            for i in range(len(face)):
                edge = tuple(sorted([face[i], face[(i - 1)]]))
                output.add(edge)
        self._edges = FiniteSet(*output)
    return self._edges
