1. The problem statement, all variables and given/known data A beam of light in air strikes a piece of glass (n=1.51) and is partially reflected and partially refracted. Find the angle of incidence if the angle of reflection is twice the angle of refraction. 2. Relevant equations n1sintheta1 = n2sintheta2 3. The attempt at a solution The angle of reflection equals the angle of incidence, which is twice the angle of refraction. Therefore, I set up the equation as: 1 * sin (2theta) = 1.51 * sin (theta) But when I try to solve for theta I get that they cancel out (sin 2theta / sin theta) just equals 2? I think I'm doing the trig wrong but I don't know why?