Let A', B', C' be the altitude feet. Let Ab, Ac be the orthogonal projections of A' on the altitudes BB', CC'. Let ra be the radical axis between the ninecircles of AbBC, AcBC. The lines ra, rb, rc concur at the ninecenter N  (only the construction of ra is shown). The parallels from the vertices to ra, rb, rc concur at the circumcenter O. The parallels to ra, rb, rc from the altitude feet A', B', C' concur at the point X(52).