Spherical Trig question

In a right spherical triangle with C = $\pi /2$ ; , you know angles A and B . How do you find the side b? Provide the formula using Napier's Pentagram.

Answer

Answers can be viewed only if
  1. The questioner was satisfied and accepted the answer, or
  2. The answer was disputed, but the judge evaluated it as 100% correct.
View the answer
The answer is accepted.