14
Inspired by F'x, here's a 2D analogue of spikey. Done with a bunch of rules because I like them, and they make it clear what is going on.
Start with a pentagon:
p = Polygon[Table[N[{Cos[t], Sin[t]}], {t, \[Pi]/10, 2 \[Pi], (2 \[Pi])/5}]];
Make a rule to split any polygon into triangles (ce...