In an acute triangle AB the heights BE and CF intersect at the orthocenter H, and M is the midpoint of BC. The line EF intersects the lines MH and BC at the points P and T , respectively. AP intersects the cirumcscribed circle of △ABC for second time at the point Q . Prove that ∠AQT=90o.(Fedir Yudin) geometrycircumcircleright angle