I always avoided half square triangles because if I cut my pieces the size in the instructions I always ended up with one triangle smaller than the other. An experienced quilter gave me a good tip. Always cut your square a half inch larger than the directions say, then cut your square on the diagonal, sew your triangles together and then press. Using a square ruler line up ruler's diagonal line with your block's diagonal seam and cut the block the size you need. A little bit of extra time but worth it. May in Jersey