Originally Posted by
Holice
A similar case happened to me many years ago about the 7/8" added to a triangle.
I had to cut a square - say 6", then divide it diagonally into a triangle, then add the 1/4" all around and then measure the base to the tip of the diagonal line. It was 6 7/8". Then it all came clear to me.
This is the one I had to draw out for myself, too.