you got a 12*9 rectangle with a 8*1 hole in the middle. now, cut it in to two parts, so they'll form a 10*10 square. it has to be two parts, no tricks, just a simple clever cut. enjoy Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image!
I think I got it: Please Register or Log in to view the hidden image! Shift the right piece up one and over to the left two.