I'm trying to prove that if I were to shine a beam of light into a prism at an angle of incidence 35°, then the angle of incidence where the light leaves the prisim is 38°. The prisim having a refractive index of 1.55, and being an equilateral triangle.

However, I'm having abit of trouble with this.

I'm aware of the rule: n=sin i/sin r

and: 1/n=sin i/sin r

but I still can't figure it out.

Can anyone tell or show me the steps to achieve this?

Thanks.