Your geese and your rectangles have to be 5 1/2 by 2 3/4 UNFINISHED. to get your 10 inch finished size.
The math: 5.5 plus 2.75 plus 2.75 (unfinished) equals 11 minus .5 minus .5 (2 seams 1/4 inch from each side of 2 seams) equals 10 inch unfinished block........ This is the math for 1/2 of the block.