hey guys i can't understand this particular code:

class Rectangle extends Shape{
 public Rectangle(Point startDiag, Point endDiag) {
  // Bottom right is relative to top left:
    bottomRight = new Point(Math.max(startDiag.x,endDiag.x) - position.x, Math.max(startDiag.y,endDiag.y) - position.y);
 }
  //rest of the code
}

in bottomRight why the new points need to be subtracted from postion.x and position.y? in comment is says "bottom right is relative to top left" i can't see it's relevance.
Where you can simply write it:

 bottomRight = new Point(Math.max(startDiag.x,endDiag.x),
                         Math.max(startDiag.y,endDiag.y));

instead of:

 bottomRight = new Point(Math.max(startDiag.x,endDiag.x) - position.x,
                         Math.max(startDiag.y,endDiag.y) - position.y);

thank guys i will really appreciate your help.