==See also==* Ford circles* Apollonian gasket* Soddy's hexlet* Tangent lines to circles* Isoperimetric point==Notes====External links==* Interactive applet demonstrating four mutually tangent circles at cut-the-knot* The Kiss Precise* XScreenSaver: Screenshots :: An XScreenSaver display hack visualizes Descartes’ theorem, in hack “Apollonian”.
* Окружность Форда* Interactive applet demonstrating four mutually tangent circles at cut-the-knot* The Kiss Precise* XScreenSaver: Screenshots :: An XScreenSaver display hack visualizes Descartes’ theorem, in hack “Apollonian”.