public void CalcLengthTest3()
        {
            Point pt1, pt2;

            pt1.x = 0; pt1.y = 0;
            pt2.x = 0; pt2.y = 0;
            float exp = 0;
            float res = PolygonClass.CalcLength(pt1, pt2);

            Assert.AreEqual(exp, res);
        }