Please help me to answer this question, not even sure where to begin. Thanks in advance

3. Pappus's Variation on the Pythagorean Theorem: Let A ABC be a triangle (not necessarily a right triangle). Let ACDE and BCFG be parallelograms whose sides DE and FG intersect at H (see the G B diagram). Let ABIJ be a parallelogram with sides AJ and BI parallel to and with the same length as CH. Prove that the area of ABIJ is equal to the sum F C A of the areas of the other two parallelograms. Solution Try this question before looking at the solution. I have E H D used this exercise as a tutorial on how to write up proofs