The points K and L on the side BC of a triangle △ABC are such that BAK=CAL=90∘. Prove that the midpoint of the altitude drawn from A, the midpoint of KL and the circumcentre of △ABC are collinear.(A. Akopyan, S. Boev, P. Kozhevnikov) geometrygeometric transformationhomothetyreflectiongeometry unsolvedTuymaada