Sunday 14 October 2007 — This is exactly 17 years old. Be careful.

Looking for an unusual dessert to make for Thanksgiving this year? How about a pie in the shape of an icosahedron? This is what Instructables is all about: two geeks spending a ton of time making 20 specially-crafted pie tins so they can bake 20 triangular pecan pies, then attach them with super magnets to create a foot-high icosahedron of pie! And how often do baking instructions make reference to the hairy ball theorem?

The comments are also awesome, as math, baking, and physics geeks chime in to debate and joke:

A piecosahedron can be defined as a regular plenty-sided pie, or, in more mathematical detail, as a delicial approximation of a 2-sphere (which is the simplest space with nontrivial pie-2) constructed out of twenty regular pi-angles. It is inextricably interrelated with its dual, the doughdecahedron.

## Comments

Stan Rogers7:17 PM on 15 Oct 2007Ned Batchelder7:51 PM on 15 Oct 2007## Add a comment: