Feuerbach's Theorem
Feuerbach's Theorem
The nine-point circle of a triangle passes through the feet of the altitudes, the midpoints of the sides, and the midpoints between the vertices and the orthocenter.
The nine-point circle is internally tangent to the incircle and externally tangent to the three excircles.
External Links
External Links
Permanent Citation
Permanent Citation
Jay Warendorff
"Feuerbach's Theorem"
http://demonstrations.wolfram.com/FeuerbachsTheorem/
Wolfram Demonstrations Project
Published: March 7, 2011