problem 4. A ray of light traveling in air strikes a flat 2.00 cm tick block of glass (n=1.50) at an angle of 25.6 degrees with the normal. Trace the light ray through the glass, and find the angle of refraction for light passing from air to glass. Answer in degrees. Note: I don't know where to start. Problem 6. The angle of incidence and the angle of refraction for light going from air into a material with a higher index of refraction are 66.1 degrees and 42.2 degrees, respectively. What is the index of refraction of this material? Note: what formula should I use?