Given a triangle ABC, AE, BF and CD are 3 medians, which intersect at the centroid G. H, I and J are the midpoints of lines BG, CG and AG respectively.[br]1. Prove that quadrilaterals AJHB, HBCI and ICAJ are trapeziums.[br]2. Prove that those 3 trapezium areas are the same.[br](Hint: Consider similar triangles)