For those of you wondering, I'll try to explain how this method…

For those of you wondering, I'll try to explain how this method works. First set up you cardboard square on your frame. The gap left over (shown in the photo) it the approx width of the protractor. If you don't have a protractor, make one out of cardboard, cutting the cardboard the same distance and hold a pencil on one end.

Owner caption September 2008 · Photo 39 of 140