Shao-Cheng Liu, The symmedian point and concurrent antiparallel
Forum Geometricorum, 9 (2009) 149--154.
Abstract: In this note, we study the condition for concurrency of the
GP lines of the three triangles determined by three vertices of a reference
triangle and six vertices of the second Lemoine circle. Here G is the
centroid and P is arbitrary triangle center different from G. We also study
the condition for the images of a line in the three triangles bounded
by the antiparallels through a given point to be concurrent.
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