The diagonals of the cyclic quadrilateral ABCD are intersecting at the point E.
K and M are the midpoints of AB and CD, respectively. Let the points L on BC and N on AD s.t.
EL⊥BC and EN⊥AD.Prove that KM⊥LN. geometryparallelogramvectortrigonometrygeometric transformationreflectioncyclic quadrilateral