For G4G12, my gift was a copy of this puzzle printed on card stock.
The essence of the puzzle is: Fit 4 1x2 rectangles and 8 squares of edge sqrt(2) into a square of edge 5.216 without overlap.
Since 3sqrt(2)+1 > 5.216, you can't stack three squares and a rectangle along one of the edges, though they come very close to fitting that way. The actual solution requires tilting 4 of the squares at an angle of about 7.875 degrees.
I discovered this packing while working on the March 2014 Math Magic puzzle by Erich Friedman. The original problem concerns unit squares and squares of area 2, but in this solution the unit squares lined up in pairs and this made a nice 12 piece puzzle for G4G12.
