The CIE 7 students explored how glass is a denser medium while the surrounding medium air is rarer. When the light passes through the interface of air-glass it bends towards the normal. Students explored the angle of refraction for the first interface is equal to the angle of incidence for the second interface since both sides are parallel.
Using Snell’s law, the final angle of emergence becomes equal to the angle of incidence thereby concluding the emergent ray is parallel to the incident ray.
