i know that but plz if u measure the angles and try to put it in equation of n = sin i / sin r answer will not be 58.7
Ohhh, I got you, yea, I get something like 22.6 - I'm sorry, I can't figure out the reason behind this, but as far as I remember when you have to find the refractive index, you use the formula, n=sin i/sin r