Here's a large cardboard
construction I made with a group of teachers from Math for America
consists of sixty identical flat pieces that lock together with
slots. The design is based on the twenty face planes of a
regular icosahedron, so the result has 5-fold, 3-fold, and
2-fold axes of symmetry.
I pre-cut the parts on a band-saw
and brought them with me. Assembling them took over an
hour and was trickier than I expected, but I learned a lot about
how to organize it next time.
The completed star is quite
rigid and for a while we suspended it from one point, so a
three-fold axis is vertical. It looked good hanging like
that, until a surprising thing happened...
To understand the design first see the "Blue
Paper Model" video,
then watch the "Teacher's Workshop" assembly video, both
Thank you everyone who
participated, with special thanks to Noah Heller for inviting
me and taking these photos.