i suck at trigonometry.

I wouldn't throw my dream away, and I'm sure you haven't but I'll just let you know I'm in college now and I'm a second year ME student, and stuff like that you don't do by hand. I'm not saying to slack off, because learning how to do it now by hand builds fundamentals, I'm just saying I wouldn't sweat it too much. At this level, we aren't expected to remember trig identities, or even some of the most basic integrals - we have tables for all of that. As far as exact angles and such - calculators. I would say the most important thing you can take away from trigonometry for wanting to be an engineer is the basic concept of it, because you will be working with a lot of complex geometry and trigonometry later on down the road.

Exact angle? That's easy, dude, 90 degrees.