I'm assuming side A is directly opposite angle , there is a side B opposite angle , and there is a hypotenuse opposite angle .
If so...
The sum of the interior angles in a triangle equals 180, so:
The Law of Sines:
Check out the wikipedia entry on the law of sines:
Law of sines - Wikipedia, the free encyclopedia
What this problem is asking is known as triangulation:
Triangulation - Wikipedia, the free encyclopedia