Bronze Hypocycloid Trefoil, Figure 3

A small trefoil knot whose cross-section is a hypocycloid, the curve made by a point on a circle rolling without slipping inside another circle with radius three times the radius of the rolling inner circle. This hypocycloid looks like a concave triangle, so there are three sides going around the trefoil knot, but they twist, so that one side runs into the next one, and they make just one side going three times around the knot. The base was made with Oregon black walnut.https://orb.binghamton.edu/mathematical_sculptures/1094/thumbnail.jp