You are welcomed to check out [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1247.0]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)