Last week, I bumped into Judith Seidel (@seidelj) at a lecture at the Museum of Mathematics. She suggested I explore a Cardioid Activity on Geometer’s Sketchpad — and just in time for Valentine’s Day too! A quick Google search yielded these resources which I forwarded to the Math Department:
1. A Geometer’s Sketchpad lesson plan:
http://mathforum.org/sanders/connectinggeometry/Cardioid.html
2. A video tutorial with doable paper/pencil/ruler instructions:
https://www.youtube.com/watch?v=qhbuKbxJsk8
3. More information about cardioids and the math behind them:
https://www.scribd.com/document/365268535/Cardioid-pdf
Karen Blumberg 