Mind Blowing Trick

2 different boxes ??

Hmm, couple of dodgy cuts in the the video which is a flag raiser. Chances are also that the middle bit - where he has 3 extras - there are some not very obvious thin gaps between the pieces that equal the 3 missing squares. Just like the one where you have some shapes that make a rectangle, rearrange them a bit and you have an apparently different sized rectangle, but there is a gap that you don't really notice.

Watch the row along the cut for the second piece from the bottom. It's clearly out of whack every time he shifts the pieces. When he puts everything back in the box, the boxes in it are 2/3rd as tall, making up the entire area of the 3 squares he's removed.

My Maths professor gave us this exerciese in high school. I couln't figure it out. Then he explained it and was quite like Slugsie said

Consider my mind blown.

Pretty cool!

http://www.moillusions.com/200
6/03/impossible-triangle-illus
ion-no2.html