National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Polyhedra Classification
This question and answer site provides a lot of basic information about polyhedra. The five regular polyhedra, "The Platonic Solids," are described.
National Council of Teachers of Mathematics
The Math Forum: Angles of an Octahedron
This question and answer site from The Math Forum with Dr. Math discusses the angle between two adjacent faces of an octahedron. Links are also provided for additional information on related subjects.