Cassandra,
Since this is an unusual size, I suggest you try doing this by paperpiecing.
Using paper, draw a rectangle 2-1/2" x 1-1/4"; then add the 1/4" all around; draw a line down the center of the rectangle; then draw diagonal lines from the corners to this center line making a "v".
Cut a 3" x 1-3/4" rectangle for the center and then cut two "almost" squares 1-3/4" x 1-1/2".
Lay the rectangle down first right side up;
place one almost square on top aligning the 1-3/4" edge right side down; turn the unit over and stitch on the diagonal line starting and ending outside the 1/4" seam allowance;
press the square toward the outside of the rectangle;
repeat on the other side, again stitching on the line, and press.
Carefully pull off the paper from the back without disturbing your stitches.
Trim away the extra fabric under the wings.
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Once you get the hang of this using the paperpiecing method, you might try doing without the paper but you will probably still have to draw the lines which you can do on the almost squares.
NOTE: if you shorten your stitch length and use a "fat" needle, removing the paper will be easier.
Hope this helps. Suzanne