\begin{tikzpicture}[scale=.8]
          \clip(0,0) circle (2.4cm);
          \tkzDefPoint(0,0){o}
          \tkzDefPoint(2,0){w}
          \tkzDefPoint(95:2){v}
          \tkzDefPoint(140:2){u}
          \tkzDrawSegment[dashed](u,v)
          \tkzDrawSegment[dashed](v,w)
          \tkzDefMidPoint(u,v) \tkzGetPoint{m}
          \tkzDefMidPoint(v,w) \tkzGetPoint{n}
          \tkzDrawCircle(o,u)
          \tkzDefLine[perpendicular=through m,K=-2.5](u,v);
          \tkzGetPoint{c};
          \tkzDrawLines[dashed](m,c);
          \tkzDefLine[perpendicular=through n, K=-1.2](v,w);
          \tkzGetPoint{d};
          \tkzDrawLines[dashed](n,d);
          \tkzDrawPoints[fill=red](u,v,w)
          \tkzDrawPoints(o,m,n)
          \tkzLabelPoint[right](o){\(z_0\)}
          \tkzLabelPoint[right=-2pt](w){\(w\)}
          \tkzLabelPoint[left](u){\(u\)}
          \tkzLabelPoint[above](v){\(v\)}
          \end{tikzpicture}