r1716

Let HaHbHc be the orthic triangle, A’ the reflection of Ha in HbHc and B’, C’ its analogous. Let Oa, Ob, Oc be the circumcenters of A’BC, B’CA, C’AB. The lines AOa, BOb, COc concur at the isogonal of the cevian quotient between the ninecenter N and the circumcenter O.


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