%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 28-02-13 auf Seite 613.
%% 
%%  Copyright (C) 2016 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{121.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pst-eucl}
%StopShownPreambleCommands
\begin{document}
\begin{pspicture}(-2,-2)(1,2)
\psset{arrowscale=2}
\pstGeonode[PosAngle={-135,-90,180}]%
  (-1.5,-.2){A}(.5,.2){B}(0,-2){D}
\pstRotation[PosAngle=90,RotAngle=60,CodeFig=true,
 CodeFigColor=blue,
 TransformLabel={\displaystyle\frac{\pi}{3}}]{A}{B}[C]
\pstRotation[AngleCoef=.5,RotAngle=\pstAngleAOB{B}{A}{C},
 CodeFigColor=red,CodeFig=true,
 TransformLabel=\frac{1}{2}\widehat{BAC}]{A}{D}[E]
\end{pspicture}
\end{document}
