%% 
%%  A DANTE-Edition example
%% 
%%  Example 36-00-91 on page 806.
%% 
%%  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{201.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks,pst-optic}
\makeatletter
\def\pstriangleA{\pst@object{pstriangleA}}
\def\pstriangleA@i(#1)(#2)(#3)(#4)(#5)(#6){{%
  \use@par
  \psline(#1)(#2)\psline(#3)(#4)\psline(#5)(#6)
  \ABinterCD(#1)(#2)(#3)(#4){A}
  \ABinterCD(#1)(#2)(#5)(#6){B}
  \ABinterCD(#5)(#6)(#3)(#4){C}
  \pspolygon(A)(B)(C)
}}
\makeatother


\begin{document}
\begin{pspicture}(7,7)
  \psaxes{->}(6,6)
  \pstriangleA[fillstyle=solid,fillcolor=red]%
     (1.98,2.38)(1.98,5)(1.98,3.8)(-1,3.8)(1,4)(4,0.8)
  \pstriangleA[fillstyle=solid,fillcolor=blue!30!red!20]%
     (0,0)(6,4)(1,5)(5,1)(2,0)(3,6)
\end{pspicture}
\end{document}