Illustration of a convex polyhedral angle. "The sum of the face angles of any convex polyhedral angle is less than four right angles."

Convex Polyhedral Angle

Illustration of a convex polyhedral angle. "The sum of the face angles of any convex polyhedral angle…

Diagram used to prove the theorem: "The sum of the face angles of any convex polyhedral angle is less than four right angles."

Face Angles of Convex Polyhedral Angle

Diagram used to prove the theorem: "The sum of the face angles of any convex polyhedral angle is less…

Illustration of polyhedral angle. "The opening of three or more planes which meet at a common point is called a polyhedral angle."

Polyhedral Angle

Illustration of polyhedral angle. "The opening of three or more planes which meet at a common point…

Illustration of two polyhedral angles that are equal.

Equal Polyhedral Angles

Illustration of two polyhedral angles that are equal.

Illustration used to show that two trihedral angles are equal or symmetrical when the three face angles of the one are respectively equal to the three face angles of the other.

Equal trihedral angles

Illustration used to show that two trihedral angles are equal or symmetrical when the three face angles…

Illustration of two symmetrical polyhedral angles.

Symmetrical Polyhedral Angles

Illustration of two symmetrical polyhedral angles.

Illustration of a sphere with a polyhedral angle whose vertex is at the center of the sphere and whose face angles are measured by the sides of the polygon, whose dihedral angles have the same numerical measure as the angles of the polygon.

Polyhedral Angle in a Sphere

Illustration of a sphere with a polyhedral angle whose vertex is at the center of the sphere and whose…

Illustration of a sphere with a polyhedral angle.

Polyhedral Angle in a Sphere

Illustration of a sphere with a polyhedral angle.