Your blue square should have been larger. Maybe 7/8 of an inch? I forget the fraction for sure. Anyway, many quilters make the square larger intentionally and then trim to fit after it is cut and sewn. Good luck!
You need to have a 1/4 inch seam allowance beyond the corner of the yellow square in order for the white triangle to fit perfectly. Your blue triangles will provide that when applied to the yellow piece.
Last edited by GrammieJan; 04-29-2015 at 05:18 PM.