This is the fastest way to fill up a notebook page without actually taking notes. Or listening to the lecture. Starting from a corner, draw a line making a wedge shape. Keep going around, maintaining the same end space, until you get sucked into the black hole in the center. Color each wedge, or print it on various photos. Print two different ones on top of each other, or create “A Quadpile printed on a Vortex Tesselation”!