Geometric figure formed by 2 or more planes that meet at at least one common point called the vertex of the angle.

A polyhedral angle is a solid angle.

A polyhedral angle is a solid angle.

### Examples

- This is a dihedral angle :

- This figure is formed by two half-planes having a common edge.

Line*AB*is the common edge of the two half-planes. - These are
**trihedral angles**in pyramids :

- There is a trihedral angle at each vertex of the base of a pyramid.

If a pyramid has a triangular base, there is also a trihedral angle at its

apex.

If a pyramid has a pentagonal base, there is a polyhedral angle at its apex.