The Griffiths points are two triangle centers associated with the Soddy triangles of a reference triangle (Oldknow 1996).
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.