If the incident ray at point A is at the critical angle between mediums 2 and 3, does the ray incident at point B refract out of medium 2 into 3? If so, what is the (i) angle of refraction at point B? If not, what is the reflected angle at point B? (ii) Draw an accurate ray diagram at point B. (iii) What is the initial angle ? at point C?

n1 = 1.70 B n2= 1.50 A n3= 1.30