Question

What is the shape of patato chip and why

Answer 1

Potato chips are curved because when they are fried in thin slices the outer part,  which contains less water than the inner part, doesn't cook evenly and this results in that curved form.

You need to consider that a potato is mainly composed of starch and water, the two are not uniformally distributed as the second is concentrated in the center; this means that the outer part is drier all will take less to be cooked when fried.

Answer 2

Potato chip are generally curved. It is easily to fry.