The first isogonic center of a Triangle is the Fermat Point. The second isogonic center is
constructed analogously with the first isogonic center except that for , the Equilateral
Triangles are constructed on the same side of the opposite Vertex. The
second isogonic center has Triangle Center Function
The first and second isogonic centers are Isogonal Conjugates of the Isodynamic Points.
See also Brocard Angle, Equilateral Triangle, Fermat Point, Isodynamic Points, Isogonal Conjugate
References
Gallatly, W. The Modern Geometry of the Triangle, 2nd ed. London: Hodgson, p. 107, 1913.
Kimberling, C. ``Central Points and Central Lines in the Plane of a Triangle.'' Math. Mag. 67, 163-187, 1994.