1. The problem statement, all variables and given/known data A plate is subjected to rays from a light source located 35 degrees above the horizon. The plate itself is tilted 12.5 degrees around its vertical axis reducing the exposure to the light source. Find the incidence angle between the light source and the front face of the plate. 2. Relevant equations 3. The attempt at a solution I believe the solution is based on trigonometry mostly, but could not sort it out... Any help or even direction would be much appreciated!