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equal areas from midpoints of ABCD (2007 Estonia Open Junior 1.2)

Source:

March 27, 2020
equal areasmidpointsgeometryparallelogram

Problem Statement

The sides AB,BC,CDAB, BC, CD and DADA of the convex quadrilateral ABCDABCD have midpoints E,F,GE, F, G and HH. Prove that the triangles EFB,FGC,GHDEFB, FGC, GHD and HEAHEA can be put together into a parallelogram equal to EFGHEFGH.