Adding two vectors is accomplished by adding the corresponding components. For instance, \[ (1,2,3) + (4,5,6) = (1+3, 2+4, 3+6) = (4, 6,9) \] A visual method for finding the sum of vectors is the parallelogram law, illustrated in this applet. The two original vectors, shown in blue and red, represent two adjacent sides of a parallelogram. The diagonal of this parallelogram is the sum of the two vectors, shown in purple.