\begin{tikzpicture}[scale=.8]
              \tkzDefPoint(0,0){z1}
              \tkzDefPoint(3,0){zo}
              \tkzDefPoint(1,0){w}
              \tkzDefPoint(1.5,0){m}
              \draw[<->, dashed] (-2.6,0)-- (5.7,0) node[right]{\(L_1\)};
              \tkzDrawCircle[color=blue](zo,w)
              \tkzDrawCircle[dashed](m,zo)
              \draw[<->, thick,color=blue](0,-2.6)--(0,2.6) node[above]{\(L\)};
              \tkzInterCC(zo,w)(m,zo) \tkzGetPoints{t}{t1}
              \tkzDrawSegments[dashed](z1,t t,zo)
              \tkzMarkRightAngle[fill=lightgray](z1,t,zo)
              \tkzDrawPoints(t,z1,zo)
              \tkzLabelPoint[below](t){\(t\)}
              \tkzLabelPoint[below right=-2pt](zo){\(z_o\)}
              \tkzLabelPoint[below left=-2pt](z1){\(z_1\)}
              \tkzDrawCircle[dashed](z1,t)
              \tkzInterLC(z1,zo)(z1,t)\tkzGetPoints{p}{q}
              \tkzDrawPoints[size=8,fill=red](p,q)
              \tkzLabelPoint[below left=-2pt](p){\(p\)}
              \tkzLabelPoint[below left=-2pt](q){\(q\)}
              \draw (3,1) node{\(C_1\)};
              \draw (3,-2.2) node[color=blue]{\(C\)};
              \draw (220:2) node{\(C_2\)};
              \end{tikzpicture}