Angles of a yard or building
1) In these days it is difficult to get a square or rectangular yard exactly fitting in all the directions of South, North, East and West. But even if it is angled by 15 to 20 degrees it is all right.
2) If your yard is not rectangular see that at least Southeast and Southwest corners have a 90 degree angle.
3) The Southwest corner should be exactly at a right angle. If it is not please correct the same. Southwest corner of your house should be should be heaviest and the walls higher and thicker and the floor a little higher.
4) If your yard is not rectangular see that at least Southeast and Southwest are a uniform shape.