public void CalculatePerpendicularPointTest_WhenLineInPlaneXYAndPosition_ThenPlumpPointIsCalculated() { var position = new Position3D(100, 100, 200); var axis = new Axis3D(new Position3D(), new Vector3D(1, 1, 0)); var plump = axis.CalculatePerpendicularPoint(position); var plump2 = position.CalculatePerpendicularPoint(axis); var expected = new Position3D(100, 100, 0); Assert.Equal(expected, plump); Assert.Equal(expected, plump2); }