# Shortbraid and other geometric cookies

What happens when you combine three recreational math artists with a fantastic pastry chef?

Last weekend, Vi Hart, Gwen FisherRuth Fisher and I got together to try this experiment. Ruth provided several colors of shortbread dough and white chocolate “glue” and a few assorted cookie cutters. Gwen took photos (shown with permission below) and Vi took a bunch of video.

Our first idea was to make polyhedra cookies. The hexagon cookie cutter seemed to suggest truncated tetrahedra, octahedra, and icosahedra. We tried making one of each.

Assembly was a bit tricky and required the use of an assortment of cardboard jigs to keep pieces in place while the chocolate dried.

While our hexagon cookies were baking, Vi got started making a rhombic dodecahedron. We used a straight-edge to cut rhombi with the correct dimensions.

She wanted to have little cut-out holes in her polyhedron, and used a rhombic cookie cutter that happened to have just the correct dimensions to tile the plane nicely.

Which, of course, got us thinking about more interesting geometric tilings. For example, non-periodic Penrose tilings. Everyone likes the kite dart tiling and we made ourselves some cookie cutters out of card stock to generate kites and darts quickly.

A real math cookie party isn’t complete with out some fractals (here we have some Sierpinski Tetrahedra)…

and some shortbread “shortbraids”. The three rings here form an 18-crossing Brunnian link.

## 3 Replies to “Shortbraid and other geometric cookies”

1. annag says:

dude, these are nifty; thanks for sharing!
maybe i should make a website, too. 😀

2. Tomek says:

Can I get the recipie? Please!

1. hawksley says:

I don’t actually have the recipe. The cookie dough was made by Ruth Fisher, a professional pastry chef. 😉