This seems really easy but I am having a really hard time getting the correct answer to this question. Any help would be much appreciated. A ray in air is incident on a glass plate whose index of refraction is 1.60. The angle of refraction is one half the angle of reflection. The angle of refraction is closest to: I know to use snell's law and theta_a = theta_r but the problem doesn't give me any angles to compute theta_b (1) sin (theta_a) = 1.60 sin (theta_b) and theta_b = 1/2 theta_r = 1/2 theta_a I'm I suppose to assume something here?