The Euler-Gergonne-Soddy triangle is the right triangle
created by the pairwise intersections of the Euler line
,
Soddy line
, and Gergonne line
.
(The triangle is always right since the Soddy and Gergonne lines always intersect
perpendicularly.) The vertices of this triangle are the de
Longchamps point
(
), Fletcher
point
(
),
and Evans point
(
) (Oldknow 1996).
It is not in perspective with .
The circumcircle of the Euler-Gergonne-Soddy triangle is the Euler-Gergonne-Soddy circle.