Triangle Problem

Essentially, you just use a combination of the Laws of Sine and Cosine for (tri)angles to find all the lengths needed to find theta.

I expect to see a more elegant approach from pie's instructor, though, seeing how this is a rather... bullfighting method.

oh, i know that, i am just too lazy to do it (and can't remember well how to do it, so i'd probably make mistakes), hence why i want someone to do it instead, and i can see their math.