Sometimes we just try to make things to hard. This is really easy. Just make your star block. when it is all sewn together, take whatever 10" sq color you want cut it in 1/2 twice to make 4 ( 5" squares). Press the square in 1/2 on the diagonal or draw a line on the diagonal. Place these squares in the corner and sew them on the diagonal. Take the corner that faces your star and fold it to match the opposite corner. Press. trim. easy peasy.
Geri in Anchorage