Well, I would probably paper piece it. Another way to go would be make a flying geese unit (lots of instructions out there to make 4 ata time), then snowball it with 2 flippy corners. Actually, you would take the finished flying goose & make another flying goose going in the other direction. A bit wasteful, but if you seam the 2 cutoff triangles, you will have some interesting patches for another project or for the quilt border.