Conway’s Circle Theorem: A Short Proof, Enabling Generalization to Polygons
Conway’s Circle Theorem: A Short Proof, Enabling Generalization to Polygons

Summary/Abstract: John Conway’s Circle Theorem is a gem of plane geometry: the six points formed by continuing the sides of a triangle beyond every vertex by the length of its opposite side, are concyclic. The theorem has attracted several proofs, even adorned Mathcamp T-shirts. We present a short proof that views the extended sides as equal tangents of the incircle, a perspective that enables generalization to polygons.

• Details
• Contents