# Spherical Trig problem

## Recommended Posts

Im trying to use spherical trig to solve a problem

In the standard method to compute the angles, I already have only the following four angles

A, a, B, b

but from these, what formula can I use to compute either C, or c?

Thanks

##### Share on other sites
It's been decades since I've done any spherical geometry, but I don't believe you have enough information. I.e., your information is under-constrained. In addition to a, A, b, B - you need c to find C, or C to find c.

Referencing [url="http://mathworld.wolfram.com/SphericalTrigonometry.html"]this link[/url], given only aAbB, you can only determine the [i]ratio[/i] of sin c/ sin C. E.g., sin c/ sin C = sin a/ sin A.

##### Share on other sites
Maybe you could clarify your notation. What are a, A, b, B, c and C?

##### Share on other sites
I don't really understand what you want, so maybe you could clarify it a bit, but if it's in any way related to computing angles of figures on the sphere, then it might help to know that angles are invariant under stereographic projection, so with this you can probably transform your problem into one in the plane.

## Create an account

Register a new account

• ### Forum Statistics

• Total Topics
628381
• Total Posts
2982360

• 10
• 9
• 15
• 24
• 11