OK...I think what you are asking is, how to define the "box" that you fly in (the sky). I am not a pattern pilot, but I too am interested. The "box" is an imaginary box that you perform your aerobatic sequences in. Roughly speaking, as I do not know what would be considered the actual dimension by the judges, but...The top of the box is as high as you will fly, from left to right or right to left. The two vertical "upline" and "downline" of the "box" are the ends. The lowest altitude you fly left to right or right to left is the bottom of the "box". The center of the "box" is an imaginary vertical line directly in front of you. To establish your "box", you will make your turns at each end of the field in the same place the same distance from your "center". At the ends of the "box", up and down lines are vertical. I think up and down lines in the middle of the "box" are at a 60 degree angle. Hope this makes sense to you. This is about all I know about the "box".