The Lucas central triangle (a term coined here for the first time) is the triangle formed by the centers of the Lucas circles of a given reference triangle .
It has trilinear vertex matrix
(1)
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where , , , and is Conway triangle notation.
The Lucas central triangle has side lengths
(2)
| |||
(3)
| |||
(4)
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Its area is given by
(5)
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where is the circumradius of the reference triangle.
The circumcircle of the Lucas central triangle is the Lucas central circle.
The following table gives the centers of the Lucas central triangle in terms of the centers of the reference triangle for Kimberling centers with .
center of Lucas central triangle | center of reference triangle | ||
incenter | isogonal conjugate of | ||
isoperimetric point | circumcenter | ||
first Eppstein point | Kenmotu point |
The Cevian triangles of Kimberling centers for , 6, 371, and 588 are perspective to the Lucas central triangle. In fact, the Cevian triangle of any point lying on the trilinear cubic
(6)
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is perspective to the Lucas central triangle (P. Moses, pers. comm., Feb. 3 2005). The anticevian triangles of for and 6 are also perspective to the Lucas central triangle (P. Moses, pers. comm., Jan. 21, 2005). The following table summarizes some perspectors of the Lucas central triangle and other named triangles.
triangle | perspector |
Lucas inner triangle | |
Lucas tangents triangle | |
symmedial triangle |