Article
Summary:
The text is about Karl Feuerbach and his remarkable theorems. First, we describe his life and the path to mathematics. Then we remember the ``small'' Feuerbach's theorem about nine points circle, with brief proof. Finally, we state the ``big'' Feuerbach's theorem about tangent circlec, and two the most interesting proofs.
Related articles:
References:
[3] Pedoe, D.:
Circles: a mathematical view. The Mathematical Association of America. 1995.
MR 1349339
[5] Švrček, J., Vanžura, J.: Geometrie trojúhelníka. Polytechnická knižnice. Praha 1988.