The Isogonal Conjugate of the Euler Line. It passes through the vertices of a Triangle, the Orthocenter, Circumcenter, the Lemoine Point, and the Isogonal Conjugate points of the Nine-Point Center and de Longchamps Point.

**References**

Casey, J. *A Treatise on the Analytical Geometry of the Point, Line, Circle, and Conic Sections, Containing
an Account of Its Most Recent Extensions with Numerous Examples, 2nd rev. enl. ed.* Dublin: Hodges, Figgis, & Co., 1893.

Pinkernell, G. M. ``Cubic Curves in the Triangle Plane.'' *J. Geom.* **55**, 141-161, 1996.

Vandeghen, A. ``Some Remarks on the Isogonal and Cevian Transforms. Alignments of Remarkable Points of a Triangle.''
*Amer. Math. Monthly* **72**, 1091-1094, 1965.

© 1996-9

1999-05-25