r787

Let At be the reflection of the foot of the A-altitude on the midpoint of AH (H being the orthocenter), and Ad the second intersection of the ninecircle and the perpendicular bisector of BC. Define analogously Bt, Ct, Bd, Cd. The lines AtAd, BtBd, CtCd concur at the De Longchamps point of the orthic triangle.


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