why does pizza's serves in a square box?

I think it's because a round box would be more difficult and costly to make. It is cheaper and easier to just use square boxes, because that is a regular box shape.

my sister works for dominos and she says its because the square boxes are easier to store and to fold..

Stability is one reason. Because square boxes are easier, cheaper and more stackable and the people making the pizza don't have to put them together. Plus, pizzas fit in them. So I guess this is the general idea.

It is the same here in the United States. We get round pizza's in a squre box also. I guess things are alot alike all over the world :)

This whole question leads to this next point... If boxes are square, why do we make pizzas round? come on you guys you knew this question was coming... As for the square boxes for round pizza, I think it is anm issue of easiness. A square box can be stored easily and folded when needed, something you just can't do with a circlular box.

in pizza hut, it's somewhat like an octagon

You know, I never have thought about this one before. I suppose they find it easier to make a square box than a circular box.

I imagine because the square boxes are easier to use haha..... but beside that i have tasted pizza in your wonderful country and found that the opposite applies to here (australia) as far as taste goes ..... Domino is great there... the best i have ever tasted anywhere.... pizza hut is ... well ... yukki anyhow just a bit of trivia for you