Suppose the isosceles prism of the figure has apex angle ? = 52.8° and index of…

Suppose the isosceles prism of the figure has apex angle ? = 52.8° and index of refraction n = 1.69. (a) what is the smallest angle of incidence for which a ray can enter the left face of the prism and exit the right face? (b) what angle of incidence ? is required for the ray to exit the prism with an identical angle ? for its refraction, as it does in the figure?