On six circumcenters and their concyclicity - Nikolas Dergiades, Francisco Javier Garcia Capitan, and Sung Hyun Lim Given triangle ABC, let P be a point with circumcevian triangle A'B'C'. We determine the positions of P such that the circumcenters of the six circles PBC', PB'C, PCA', PC'A, PAB', PA'B are concyclic. There are two such real points P which lie on the Euler line of ABC provided the triangle is acute-angled. We provide two simple constructions of such points. ✪ ✪ ✪ ✪ ✪ Link tải tài liệu: LINK TẢI TÀI LIỆU Theo LTTK Education
