r541

Let A'B'C' be the orthic triangle, and A"B"C" be the extouch triangle of A'B'C'. The ellipse with focii A', A" going through B' goes also through C', and is bitangent to ABC in these points. If we define analogously two other ellipses, their principal axes concur at X(185), and their centers being Oa, Ob, Oc , the lines AOa, BOb, COc concur at the symmedian point K.


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