Question

the angle of incidence and the angle of emergence are of ...... measures

Answer 1

The angle of incidence and the angle of emergence (reflection) are of equal measures

It is one of the laws of reflection.

Hope it helps! :)

Answer 2

The Angle of incidence and the Angle of emergence, both are equal.

Now, you are using glass block with parallel sides.

This incident ray will also be parallel to the emergent ray, which is the angle of refraction.

The rays of light entering a glass block which refracts, so that it emerges on the other side parallels to the incident ray.