Since we don't want to digress too far off topic in the Mystery Quilt thread, here are ways to make flying geese, Other ideas will doubtless be along shortly...

The basic model:

Take:

One quarter-square triangle (QST), that is one with the straight grain along the long side of the triangle, with two 45deg angles and a 90deg angle at the top. Usually cut by dividing a square diagonally, twice, hence the name. The square/long-side of the triangle will measure the finished width of the FG unit plus 1¼ inches

One square cut diagonally once to make 2 half-square triangles (HST), The short sides of the triangles will be on the straight grain, each side of the 90deg corner. The short sides will measure finished height of the FG unit plus seven eighths of an inch.

Sew the long edges of the HSTs to the short edges of the QSTs, matching the 45deg points. You will have 2 little 'dog ears' at the top. Press the unit and trim off the points, and check the size of the unit, which should be finished size plus ½ inch seam allowances (ie ¼ extra all the way round).