Why does trigonometry sound so scary? Often in the world of physics, and when the real world comes crashing into the lab, we need to use sine, cosine, and tangent in our calculations for having a way of relating the angles in a triangle to the lengths of the sides. Here is a simple tutorial that will act as a refresher if you have forgotten, or a brand new look at a useful set of equations if you never took trig.
http://www.physics.uoguelph.ca/tutorials/trig/trigonom.html