1. The problem statement, all variables and given/known data look at the figure and prove that sina'=nsinb. We have given a, b, a', b' and n http://s32.postimg.org/n7rnu0khx/image.png 2. Relevant equations sinb'/sina'=1/n 3. The attempt at a solution But in the equation we have b, not b'. I made the figure. How would the correct one be?