Two-Pancake Problem

The Two-Pancake Problem is an introductory problem in topology that asks whether two pancakes can be bisected with a single cut. The solution generates a theorem, called the Two-Pancake Theorem, that the area of any two pancakes having an arbitrary two-dimensional shape can both be perfectly bisected with one straight line (one cut of a knife). Its proof is an illustration of the properties of continuous functions. It is the two-dimensional version of the three-dimensional Ham Sandwich Theorem.