1. The problem statement, all variables and given/known data A light beam incident on a glass slide at an angle of 60 ˚, being partly reflected and partly refracted. It notes that reflected and refracted beams are each at 90 ˚ What is the refractive index of glass? 2. Relevant equations n1sinσ1 = n2sinσ2 3. The attempt at a solution σ1 = 60° σ2 = 30° sinσ1 / sinσ2 = n So, is this right?