# Napier's Right Spherical Triangle

## Description

Illustration of a right spherical triangle and the five circular parts placed in the sectors of a circle in the order in which they occur in the triangle. "The ten formulas used in the solution of spherical right triangles can be expressed by means of two rules, known as Napier's rules of circular parts."

## Keywords

analytic geometry, angle, Napier, Napier's rules, right spherical triangles, sector, trigonometric, trigonometry

## Galleries

## Source:

George N. Bauer, PH.D. and W.E. Brooke, C.E., M.A. *Plane And Spherical Trigonometry* (Boston: D.C. Heath & Co., 1917) 138

Courtesy the private collection of Roy Winkelman