%% 
%%  A DANTE-Edition example
%% 
%%  Example 29-02-5 on page 566.
%% 
%%  Copyright (C) 2011 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[]{article}
\pagestyle{empty}
\setlength\textwidth{129.70511pt}
\setlength\parindent{0pt}

\usepackage{pst-eucl}

\begin{document}
\begin{pspicture}(-1,-1)(2.5,2)
  \pstGeonode[PointSymbol=none,
    PosAngle={-45,45,135}]{A}(0,2){B}(2.5,2){C}
  \pspolygon(A)(B)(C)
  \psset{arrows=->,linecolor=red}
  \pstMarkAngle{C}{A}{B}{$\alpha$}
  \pstMarkAngle[MarkAngleRadius=1]{B}{A}{C}{$\alpha$}
  \pstMarkAngle[linestyle=dotted]{B}{C}{A}{$\gamma$}
  \pstMarkAngle[arrowscale=2,MarkAngleRadius=-0.75]{A}{B}{C}{}
\end{pspicture}
\end{document}