Archive for April, 2016

Descartes’ Circle Theorem

April 9, 2016

Finding a proof of Steiner’s Porism not using inversive geometry proved a tough task, so I decided to look at Descartes’ Circle Theorem. If we include both the inscribed and circumscribed circles this actually represents the simplest case of a Steiner Chain, with three circles between the inner and outer circles. For more, see the Geometry Page.