# The General Triangle Is Unique

 Title: The General Triangle Is Unique Author: Joachim Breitner (joachim /at/ cis /dot/ upenn /dot/ edu) Submission date: 2011-04-01 Abstract: Some acute-angled triangles are special, e.g. right-angled or isoscele triangles. Some are not of this kind, but, without measuring angles, look as if they were. In that sense, there is exactly one general triangle. This well-known fact is proven here formally. BibTeX: @article{General-Triangle-AFP, author = {Joachim Breitner}, title = {The General Triangle Is Unique}, journal = {Archive of Formal Proofs}, month = apr, year = 2011, note = {\url{https://isa-afp.org/entries/General-Triangle.html}, Formal proof development}, ISSN = {2150-914x}, } License: BSD License