Complete the ray diagram (ABCD is a rectangular glass block). An incident ray strikes the corner of the block.

Hint: We are given a rectangular glass block and a light ray strikes the corner of the block so as the light ray enters the medium of higher refractive index, it bends towards the normal and when emerges out of the medium to the same medium, it gets refracted away from the normal.

Complete answer:
We will draw the refracted ray of the incident ray that strikes the corner of the rectangular block. Since the light ray is entering a denser medium the light ray will move towards the normal of the interface. The angle of incidence is the light ray is $i$ at point A and then refracts at an angle $r$ towards the normal and travels through the slab and emerges out of it and refracts away from the normal at an angle of emergence $e$ .

When a ray enters the medium it deviates away from the straight line of the incident ray and the angle is called the angle of deviation. And when the ray travels out of the rectangular block it rises parallel to the non- deviated path of the light.

Note: When the light ray travels from a medium of lower refractive index to a region of higher refractive index, the light ray bends towards the normal and vice-versa. If in the given case, had there been no change in the medium the light ray would travel straight path which is parallel to the emergent ray. Denser medium has more refractive index than rarer medium and in this case, glass has a higher refractive index.