Orthocenter and Circumcenter are Isogonal
The classical centers are centroid, the circumcenter, the orthocenter and the incenter.
The orthocenter (H) and the circumcenter (O) are shown below. The line AH and AO are
isogonal with respect to sides AB and AC. Go ahead and draw lines BH and BO as well as
CH and CO. Confirm that they are isogonal.