When you create a quadrilateral solid-filled area, the sequence of the third and fourth points determines its shape. Compare the following illustrations:
Notice that to create the quadrilateral area, both the top and bottom edges are specified from left to right. If you specify the first point on the right and the second point on the left, then the third and fourth points should also be in a right-to-left direction. As you continue to specify pairs of points, be sure to continue this zigzag sequence to ensure the results you expect.