Spherical Triangle: Napier's Rules
Spherical right triangles and Napier's Rules [url]http://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Spherical_trigonometry_Napier_right-angled.svg/443px-Spherical_trigonometry_Napier_right-angled.svg.png[/url]
Spherical Triangle: Napier's Rules
Information: Spherical Triangle: Napier's Rules