A rectangular slab of glass with unknown index of refraction is on top of the surface of a liquid that also has an unknown index of refraction. A light beam is incident from air into the glass such that the part of the beam that strikes at the glass/liquid boundary is incident at the critical angle which is 65 degrees. The angle of incidence between the air/glass boundary is 40 degrees.

Required:
a. Determine the index of refraction of the glass.
b. Determine the index of refraction of the liquid.