An acute triangle is a triangle that has all angles less that 90∘ (90∘ is a Right Angle). Let ABC be a right-angled triangle with ∠ACB=90∘. Let CD be the altitude from C to AB, and let E be the intersection of the angle bisector of ∠ACD with AD. Let EF be the altitude from E to BC. Prove that the circumcircle of BEF passes through the midpoint of CE. geometryangle bisectorcircumcircle