\begin{tikzpicture} \tkzInit \tkzDefPoints{0/0/O,5/0/A,3/4/B} % Don't forget {} to get, () to use \tkzFillAngle[size=4cm,left color=white, right color=red!50](A,O,B) \tkzDrawLines(O,A O,B) \tkzDrawPoints(O,A,B) \end{tikzpicture}