%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 28-02-17 auf Seite 615.
%% 
%%  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
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%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{145.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pst-eucl}
%StopShownPreambleCommands
\begin{document}
\begin{pspicture}(-2,-2)(2,2)
\psset{PointSymbol=none,CodeFig=true,
 CodeFigColor=red,RightAngleType=german}
\pstTriangle[linewidth=1pt]%
  (-2,-1){A}(1.5,2){C}(0,-1){B}
\pstProjection{A}{B}{C}[I] \pstProjection{A}{C}{B}
\pstProjection{C}{B}{A}[K]
\pspolygon[linestyle=dotted,linewidth=1pt](I)(B')(K)
\pstLineAB[linestyle=dashed]{B}{I}
\pstLineAB[linestyle=dashed]{B}{K}
\end{pspicture}
\end{document}
