Polyhedral angles

A polyhedral angle is formed at a point (the vertex) by three or more plane angles (faces) meeting at that point, with each pair of faces forming a dihedral angle. The simplest example is the corner of a cube, where three square faces meet.

Important properties

• A polyhedral angle is defined by its vertex and the planes (faces) passing through it.

• The number of faces must be at least three.

• Each pair of adjacent faces forms a dihedral angle.

• The sum of the plane angles at the vertex is less than $360^ ext{o}$ (or $2 ext{π}$ radians) for the polyhedral angle to be convex.