1. The problem statement, all variables and given/known data A ray of light falls on the surface AC of a prism with a straight angle and with two sides equal. For which incidence angle the ray won't come out of the surface AB. The index of refraction for the prism is n=2. 2. Relevant equations sina/sinb=n2/n1 3. The attempt at a solution sinb=1 so sina=n2/n1=1/2 the angle is pi/6 rad. Am I right?