1. The problem statement, all variables and given/known data Problem #199 http://img88.imageshack.us/img88/8008/scan0001vd.jpg [Broken] Solution http://img21.imageshack.us/img21/2131/199hg.jpg [Broken] 2. Relevant equations Why is the angle from VB/A 20 degrees from the solution diagram? It would seem that I had to know that direction of VB/A had the same angle as VA in terms of the geometry (if two parallel lines are cut by a transversal, its alternating interior angles are equal). I just don't see how you can assume that. 3. The attempt at a solution Since drawing a triangle is the first part, I don't have any "attempt" at it yet.