I am surprised. The layer cake I had with the pinking edges was ten inches to the edge of the fabric. It took me awhile to figure that out. If you had had my layer cake, the ten inch squares you made would have worked perfectly. Sorry yours didn't.
I just cut some 2 1/2 inch strips that were 2 1/2 on one edge and 2 1/4 on the other. I have to be more careful when I cut!! So I do feel your pain.
Dina