This Thursday’s SUMS talk will be given by Stephan Tillmann. Pre-cut, circular pizza will be available after the talk. Abstract: Given a polygon, can you cut it up and reassemble the pieces to obtain a rectangle? Given two rectangles of the same area, can you cut one up and reassemble the pieces to obtain the other? Given a rectangle, can you cut it up into a finite number of squares? In this talk, I’ll discuss these questions about polygons, as well as the analogous questions about 3-dimensional polytopes, and mention various questions that remain open.