CatalinBordea 23.08.2019 19:31 The orthocenter $ H $ of a triangle $ ABC $ is distinct from its vertices and its circumcenter $ O. $ $ M,N,P $ are the circumcenters of the triangles $ HBC,HCA, $ respectively, $ HAB. $ Prove that $ AM,BN,CP $ and $ OH $ are concurrent. Attachments:
sinxcosxtanxcotx 23.08.2019 19:42 not a solution Note that $AHMO$ is a parallelogram hence we are done since they all pass through midpoint of $OH$