# A Collinearity from the Medial and Excentral Triangles

A Collinearity from the Medial and Excentral Triangles

Let ABC be a triangle with excentral triangle A'B'C'. Let H be the orthocenter of ABC, I the incenter of the medial triangle of ABC, and O the circumcenter of A'B'C'. Then H, I, and O are collinear and I bisects HO.