\begin{tikzpicture} \tkzDefPoint(0,0){O} \tkzDefPoint(1,1){A} \tkzDefPoint(4,2){B} \tkzGetVectxy(A,B){v} \tkzDefPoint(\vx,\vy){V} \tkzDrawSegment[->,color=red](O,V) \tkzDrawSegment[->,color=blue](A,B) \tkzDrawPoints(A,B,O) \tkzLabelPoints(A,B,O,V) \end{tikzpicture}