\begin{tikzpicture} \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black] \tkzSetUpLine[line width=1] \tkzDefPoints{0/0/P, 4/0/Q, 1/0.5/B, 1/2/A} \tkzInterLL(P,B)(Q,A) \tkzGetPoint{C} \tkzDrawLine[color=red](P,A) \tkzDrawLine(Q,A) \tkzDrawLine(P,Q) \tkzDrawLine[add=0 and 0.5](P,C) \tkzDrawSegments(B,Q) \tkzDrawLine(P,Q) \tkzDrawPoints(P,C,A) \tkzDrawPoints[fill=red,color=red](Q,B) \tkzLabelPoint[below](P){$P$} \tkzLabelPoint[below](Q){$Q$} \tkzLabelPoint[below](B){$B$} \tkzLabelPoint[below](C){$C$} \tkzLabelPoint[below](A){$A$} \end{tikzpicture}