Okay Maggie, I understand when you say that you 'won't be able to square' it up. If you cut the width of the fabric with the print the length cut will cut the star in half, so no matter what way you cut you end up with a partial star. If this fabric is going to be triangles it won't show that much because the cross cuts are going to cut the stars in 1/2 anyways.
Does that make sense to you?