A ray of light travels through 3 materials whose surfaces are parallel to each other. The refracted rays (but not the reflected rays) are shown as the light passes through each material. A ray of light strikes the a-b interface at a 50 degree angle of incidence. The index of refraction of material a is na = 1.20. The angles of refraction in materials b and c are, respectively, 43 degrees and 60.1 degrees. Find the indices of refraction in these two media.