English

A simple proof of Feuerbach's theorem

History and Overview 2016-10-14 v1

Abstract

The theorem of Feuerbach states that the nine-point circle of a nonequilateral triangle is tangent to both its incircle and its three excircles. We give a simple proof of this theorem.

Cite

@article{arxiv.1610.03962,
  title  = {A simple proof of Feuerbach's theorem},
  author = {Franz Hofbauer},
  journal= {arXiv preprint arXiv:1610.03962},
  year   = {2016}
}
R2 v1 2026-06-22T16:19:29.072Z