A sliver of the surface of a Sphere of Radius cut out by two planes through the azimuthal axis with
Dihedral Angle . The Surface Area of the lune is

which is just the area of the Sphere times .

**References**

Beyer, W. H. *CRC Standard Mathematical Tables, 28th ed.* Boca Raton, FL: CRC Press, p. 130, 1987.

© 1996-9

1999-05-25