"The" Griffiths point Gr is the fixed point in Griffiths' theorem. Given four points on a circle and a line through the center of the circle, the four corresponding Griffiths points are collinear (Tabov 1995).
Let the inner and outer Soddy triangles of a reference triangle 
be denoted 
and 
, respectively. Similarly, let the tangential
triangles of 
and 
be denoted 
and 
,
respectively. Then the inner (respectively, outer) Griffiths point Gr (respectively,
) is the perspector
of 
and 
(respectively, 
and 
)
(Oldknow 1996). The Griffiths points lie on the Soddy line.
They have triangle center functions
 |  |  |
(1)
|
 |  |  |
(2)
|
which are Kimberling centers 
and 
, respectively.
