By George Hart for the Museum of Mathematics

Here’s a challenge: Make something cool from binder clips.

It will be tough to beat this spherical construction by Yang Enqi. Using one handle, five clips of one color are linked cyclically into a pentagon. Using the other handle, twelve of these pentagons assemble like a dodecahedron to make the sphere. The above image is centered on a 3-fold joint, where three pentagons meet using one of the handles. The image below is centered on one of the pentagons, made from the other handle. Every clip has one handle in each of these two arrangements.

Notice that just six colors are used for the twelve pentagons, with opposite pentagons having the same color.

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