With the measures I will give you, you will obtain a four units Flying Geese block
10" x 5 3/4" (once trimed).
Cut ONE large square 6 1/2" for the 4 centre triangles
and FOUR 3 1/2" for the 8 (what I call) background triangles.
With a sharp pencil draw a diagonal line on the wrong side of each small square.
Place two small squares on the big square, right side against right side, as shown above.
Sew along each side of the line, at 1/4".
Cut on the line.
This is what you obtain.
Open and press.
On each obtained piece place one square, right side against right side.
Again, sew at 1/4" on each side of the line and cut on the line.
Doing so, you obtain four rectangles 5 3/4" x 3 1/8".
Trim the sides.
Piece them together. Press without opening.
Then trim the four sides to get a perfect 10" x 5 3/4" rectangle.