\begin{tikzpicture}[vect/.style={->, shorten >=3pt,>=latex'}] \tkzDefPoint(0,0){A} \tkzDefPoint(5,0){B} \tkzDefPoint(1,2){C} \tkzDefPointWith[colinear=at C](A,B) \tkzGetPoint{G} \tkzDefPointWith[colinear=at C,K=0.5](A,B) \tkzGetPoint{H} \tkzLabelPoints(A,B,C,G,H) \tkzDrawPoints(A,B,C,G,H) \tkzDrawSegments[vect](A,B C,H) \end{tikzpicture}