Let O be the center of the circle ω circumscribed around the acute-angled triangle △ABC, and W be the midpoint of the arc BC of the circle ω, which does not contain the point A, and H be the point of intersection of the heights of the triangle △ABC. Find the angle ∠BAC, if WO=WH.(O. Clurman) geometrymidpointcircumcircleequal segments