# Extouch Triangle in Poncelet Porism

What is this about?

A Mathematical Droodle

What if applet does not run? |

|Activities| |Contact| |Front page| |Contents| |Geometry|

Copyright © 1996-2018 Alexander BogomolnyThe applet attempts to illustrate a property of the extouch triangles involved in the Poncelet porism: given two circles, O(R) and I(r), let ABC be a generic triangle inscribed into O(R) for which I(r) serves as an excircle. If d, the distance between the centers of the circles satisfies

What if applet does not run? |

... to be continued ...

### References

- L. Emelyanov and T. Emelyanova,
__Euler’s Formula and Poncelet’s Porism__,*Forum Geometricorum*, Volume 1 (2001) 137–140 - W. Gallatly,
*The Modern Geometry of the Triangle*, Scholarly Publishing Office, University of Michigan Library (December 20, 2005)

|Activities| |Contact| |Front page| |Contents| |Geometry|

Copyright © 1996-2018 Alexander Bogomolny