LaTeX-examples/tikz/smaller-angle/smaller-angle.tex

\documentclass[varwidth=true, border=2pt]{standalone}
\usepackage{tkz-euclide}
\usetkzobj{all}

\begin{document}
\begin{tikzpicture}
    \tkzSetUpPoint[shape=circle,size=10,color=black,fill=black]
    \tkzSetUpLine[line width=1]
    \tkzDefPoints{0/0/P, 1.5/0/R1S, 3/0/R1, 1/1/G, 1/2/R2}

    \tkzMarkAngle[arc=lll,size=1.2cm,color=red,fill=red!20](R1S,P,R2)
    \tkzDrawLine[add=0 and 0.3,color=green](P,R1)
    \tkzDrawLine[add=0 and 0.6](P,R2)
    \tkzLabelPoint[below left](P){$P$}
    \tkzLabelPoint[below](R1S){$R_1'$}
    \tkzLabelPoint[below](R1){$R_1$}

    \tkzInterLC(P,R1)(R1S,P) \tkzGetPoints{D}{E}
    \tkzInterLC(P,G)(R1S,P) \tkzGetPoints{F}{R2S}
    %\tkzDrawCircle(R1S,D)
    \tkzLabelPoint[below](R2S){$R_2'$}
    \tkzLabelPoint[above left](R2){$R_2$}
    \tkzDrawLine[add=0 and 1,color=green](P,R2S)
    \tkzMarkAngle[arc=l,size=0.8cm,color=green,fill=green!20](R1S,P,R2S)
    \tkzDrawPoints(P, R1S, R1, R2,R2S)
\end{tikzpicture}
\end{document}