There is just one angle of incidence (beta) onto a prism for which the light inside an

Question:

There is just one angle of incidence $\beta$ onto a prism for which the light inside an isosceles prism travels parallel to the base and emerges at that same angle $\beta$, as shown in Figure P18.57.

a. Find an expression for $\beta$ in terms of the prism's apex angle $\alpha$ and index of refraction $n$.

b. A laboratory measurement finds that $\beta=52.2^{\circ}$ for a prism that is shaped as an equilateral triangle. What is the prism's index of refraction? image text in transcribed