Click and drag a near a vector tip to change its magnitude and direction.You may have to search for the sensitive spot to grab a vector.
The magnitude and direction will be updated as you change the vector.
Check "Show Resultant" and "Show Components to see the sum of the vectors and the values in the information box.
The vectors are represented by x and y components, and by their magnitude and angle.
The sum of two vectors is the sum of their components, displayed as a result with the magnitude and angle those components generate.
If V1 is (x1, y1) and V2 is (x2, y2),
their sum is V3 = (x1 + x2 , y1 + y1).