public void TestAllArea() { Box box = new Box(); Material Paper = new Paper(50, 50); Material Film = new Film(50, 50); Paper = gurl.CutRectangle(Paper); box.Add(Paper); Paper = gurl.CutRectangle(Paper); box.Add(Paper); double expected = 49 * 49 + 48 * 48; double actual = box.AllArea(); Assert.AreEqual(expected, actual); }