de Malves's theorem
De Malves's theorem states that given a tetrahedron in which the edges meeting at one vertex, X, form three right angles (i.e. the tetrahedron is the result of chopping off the corner of a cuboid), the square of the face opposite X is equal to the sum of the squares of the other three faces.
Related category GEOMETRY
Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact