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