Problem: The equilateral glass prism shown has an index of refraction of 1.55. The prism is surrounded by air. A ray of light is incident on the middle of the left face of the prism.
Part A: What is the smallest angle of incidence for which the ray of light will emerge from the right face of the prism?
Any help I can get on this problem is greatly appreciated! I'm not too familiar with this problem.