Circles Segments
Roll two points around two circles and see what patterns the segments make. Inspired by a FB post from Sue VanHattum.
The inner & outer numbers are the radii of the circles. Or you can drag the triangular points. The times number is to adjust how many times the points go around. Faster is a multiplier for the point on the outer circle. Otherwise they go at the same speed rather than the same angular velocity.
This also reminded me of problems like the Pentagram of Venus, which turns out to be the source of the gif Sue posted! Cf.
I made an applet for that one some time ago (or with a link to John Carlos Baez's nice exposition). But I added the red point from blue perspective and vice versa to look at the connections. The path of the points from those perspective have interesting connections to the segment path!