I have a picture of a one block wonder under construction. None of the half hexagons are sewn together to form a full hexagon. You lay them out in rows, then sew together across the row. Then sew the rows together. Some of your hexagons will be split between the top and bottom to make the edges straight. I also use half triangles on the right and left side to make them straight, but the ballerina quilt seems to be just cut off on the sides. Hope this helps. Ann