In parallelogram ABCD, points E and F are the mid-points of sides AB and CD respectively. Diagonals AC and BD intersect at O. Lines EO and FO are drawn.
(i) Prove that △AOE and △COF are congruent.
(ii) Hence, show that area(△AOE)=area(△COF).
(iii) Prove that the area of quadrilateral AOCF is equal to the area of quadrilateral BOED.