Given a line having trilinear coordinate equation
with respect to a reference triangle , the point
is called the trilinear pole of the line with respect to (Kimberling 1998, p. 38).
The following table gives the trilinear poles for some named lines.
| line | trilinear pole | Kimberling center | |
| antiorthic axis | incenter | ||
| Brocard axis | focus of the Kiepert parabola | ||
| de Longchamps line | third
Brocard point | ||
| Euler line | |||
| Fermat axis | Tixier point | ||
| Gergonne line | Gergonne
point | ||
| Lemoine axis | symmedian
point | ||
| line at infinity | triangle centroid | ||
| Nagel line | Yff parabolic point | ||
| orthic axis | orthocenter | ||
| Soddy line | |||
| van Aubel line |
Let
be the intercept of the line
and
, and let
be the harmonic conjugate
of
with respect to
and
.
Similarly define
and
.
Then
is the Cevian triangle of the trilinear pole of
.