To further clarify

, confound

or confuse

, (circle one)
The Critical Angle relates to total internal reflection that occurs
inside the prism where the light ray is traveling through the dense glass and approaching the boundary with the less dense air outside the prism. This is the behavior of light rays inside the prism only and not the behavior of rays of light entering the prism.
Reflection occurs when the angle of approach to the boundary wall is greater than the Critical Angle. Refraction occurs when the angle of approach is less than the critical angle. When the approach is at the Critical Angle the emerging light ray refracts at 90 degrees, follows the boundary between the glass and the air and the light beam emerges at a corner point of the prism.