What happens to the light ray when a transparent material with two curved surfaces is placed in its path ?

What happens to a light ray when it passes through a transparent medium bounded by plane surfaces which are inclined to each other ?

What happens to a ray travelling parallel to the principal axis ?

What are the favourite light rays for plants?

How do rays bend when they are incident on a curved surface ?

what happens to the value of the product when we multiply two proper fractions?

What happens to a ray that is incident on a curved surface separating the two media ? Are the laws of refraction still valid ?