If we have two points, what will happen if we add their coordinates? If point has coordinates and point has coordinates , then . It seems that there is nothing special about these points, but let us look at their position in the Cartesian coordinates.
Notice that if we add another point on the origin, the four points form a parallelogram. Now the question is, is this always the case? Try plotting two points and add their coordinates several times and see if the four points form a parallelogram. What do you observe? » Read more