Nine point circle

Revision as of 18:48, 4 November 2006 by I_like_pie (talk | contribs)

Also known as Euler's circle or Feuerbach's circle, as its name introduces itself that the nine point circle goes through nine points, which are a given triangle $\triangle ABC$'s feet of altitude dropped from three vertices $A,B$, and $C$, usually denoted as $H_A,H_B,H_C$, and midpoints of three sides, as $M_A,M_B,M_C$, and three Euler points $E_A,E_B,E_C$.

Invalid username
Login to AoPS