Cross Puzzle with 4 pieces

You asked if the puzzle in TechLab withfour pieces actually reassembles into one large square.
 Two small squares are easy.
The hint posted alongsidethis puzzle is that the square has twice the area of the cross. The only waythis can be, using the same four pieces, is if the square has a hole in it withthe same area as the cross. We will be the first to admit this is a sneakysolution.
In this case, the hole isactually the same shape as the cross. The drawing shows thecross pattern with one piece rotated into position as a corner of the squarepattern.