University of Georgia
University of Georgia: Inter Math: Edge
This site gives a description of edge along with a visual representation. Be sure to use the links to related terms, everyday examples, challenging problems, more information, and the interactive check point located in the left-hand column.
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.