As an exercise the first thing you should do in these kinds of situations is draw a diagram with every piece of information involved and then convert those to expressions and/or equations. I think it's fair to ask you to do that first and then show us where you went wrong or had trouble.
By creating a graph with all the angles and lengths along with a line by line set of mathematical expressions/equalities, it will not only help you but be easier for us as well.
Please understand that sometimes when people are tired, having these things already prepared in advance will help us and show that you have put in effort. This is not directed at you per se, but it is a general statement that applies to all posters and I am not taking any shots at you in any way.