If you have ordered a large pizza and you feel guilty after ordering it then you should not! Because according to a pizza graph, you should always order a large pizza. A circular shape of pizza area increases with the square of radius.
It means if you have ever ordered multiple smaller sizes pizza thinking you are getting a better deal. Then you are wrong you actually get les pizza with your money. It’s always good to order a large pizza rather than ordering different small sizes of pizza. (即, two mediums.)