try graphing the vectors on a pair of axes. you should be able to use trig ratios to find the x and y co-ordinates of each.
let (a,b) be the coordinates of the first and (c,d) the coordinates of the second.
then you want the vector that terminates at (a - c, b - d). then you can describe that point in terms of its distance from the origin and the angle it makes with the positive x-axis