Actually, I use the (reverse tangent function) - I don't remember the proper name for it - to get the angles.
I use basic trig and geometry a LOT! (Didn't get much further than the basics, but they sure are useful!)
I have learned a lot the backwards way - by doing it wrong and THEN figuring out how I SHOULD have done it!
Ah, well. Learn and live.
Some things just are not interchangeable.