how to do trig?

If you are trying to find the sine, cosine or tangent remember the following:

SOHCAHTOA

S = O/H

C = A/H

T = O/A

This will help a lot

This is a broad topic that obviously can't be covered in a concise answer.  This may get you started:

http://www.purplemath.com/modules/index.htm

{It's a pretty good website......the trig topics are at the bottom.....you can click on the Switch to a listing of the lessons "in order"  hyperlink at the top of the page..... }