fundamental theorem on isogonal lines
Let be a triangle![]()
and three concurrent lines at .If are the respective isogonal conjugate
![]()
lines for , then are also concurrent
![]()
at some point .
An applications of this theorem proves the existence of Lemoine point (for it is the intersection![]()
point of the symmedians
![]()
):
This theorem is a direct consequence of Ceva’s theorem (trigonometric version).