...stated : I. The sine of the middle part is equal to the product of the tangents of the adjacent parts. II. The sine of the middle part is equal to the product of the cosines of the opposite parts. 84:. In the right spherical triangles considered in this work, each side is taken less...

...noncontiguous parts the opposite parts. Napier's rules may be stated as follows: 1. The sine of any middle part is equal to the product of the cosines of the two opposite parts. 2. The sine of any middle part is equal to the product of the tangents of the two adjacent parts. (a)...