A ray of light is incident on a glass prism of refractive index μ and refracting angle A. If it just suffers total internal reflection at the other…

Obtaining a relation between angle of incidence, angle of prism and critical angle \[\begin{gathered} \because \text { the light ray ji } \\ \therefore \angle r_{2}=\angle i_{c} \\ A=r_{1}+r_{2} \\ A=r_{1}+i_{c} \end{gathered} \] From Snell's law at surface AB \[\begin{aligned} & \sin i=\mu \cdot \sin r_{1} \\ & \sin i=\mu \cdot \sin \left(A-i_{c}\right) \end{aligned} \]