Hello everyone!

This is a really tricky problem for me; I have no clue where to start. If anyone could spare some advice, I'd appreciate it.

In rectangle ABCD points F and G lie on segment AB so that AF = FG = GB and E is the midpoint of segment DC. Also, segment AC intersects segment EF at H and segmentEG at J. The area of rectangle ABCD is 70 square units. What is the area of triangle AHF?