You are welcomed to check out [url=]EJS version of Vector addition (sum of two vectors)[/url],too!
This java applets try to show : How to add two vector A and Binto vector CHow to play:
  1. There are two methods to form a vector
  2.    1. Vector A/B originate from center of the window
      Left click anywhere inside the window to form vector A or B
       2. Vector A/B originate from where you first  click the button
      Drag and lift the left mouse button to form vector A or B     Vector will move to center of the window.

  • The program will show you how to add two vector A and B into C

    C = A + BorC = B+ A
    C = A - BorC= -B + A
    A - B can be transformed to A + (-B)
  • press reset button or right click the mouse button to reset.
         Parameters are reset to default values.  
  • select info checkbox to show more information.
         X,Y components of each vector ...  
       How to process more than two vectors :
    SUM= A + B + C + D
    = (A + B) + (C+D)
    = E+ F
    E = A + B and F= C + D
     Could you figure out how to process SUM = A + B + C ?
    3-D version

    The following is a flash demo for the above java applet.

    How to form a 3_D vector
    When you form two vector A and B Drag the right mouse button to change the viewing angle. Drag near the origin to change the its position.(displacement)