18. Draw the ray diagram showing the passage of the ray through the prism \( A B C \). A ray \( P Q \) incident on the face \( A B \) as shown in the figure, emerges from the face \( A C \) such that \( A Q=A R \). If the angle of the prism is \( 60^{\circ} \) and refractive index of the material of the prism is \( \sqrt{ } 2 \), then determine the values of angle of incidence and angle of deviation.
