Tuesday, May 18, 2021

1703. Pro-Orthiac Triangles and Concurrent Euler Lines

3 comments:

  1. X(1112) is Feuerbach point of orthic triangle for acute ABC.

    ReplyDelete
  2. https://www.facebook.com/photo/?fbid=1187682567974504&set=gm.1173840176063020

    ReplyDelete
  3. Known result.
    The altitudes are bisectors of the orthic triangle.
    Therefore it is application of the following I have posted to Hyacinthos
    Let ABC be a triangle.
    Denote
    Ab, Ac = the orthogonal projections of A on BI, CI, resp.
    La = the Euler line of AAbAc
    Similarly Lb, Lc
    La, Lb, Lc concur at the Feuerbach point of ABC. αντρέας χατζηπολάκης

    ReplyDelete

1987. Circumcenter On Euler Line

 Let H=X(4)-Orthocenter of ABC. A 1 B 1 C 1 cevian triangle of H. B1 A , C1 A are reflections of B1, C1 on A. L A , line through B1 A , C1...