%% 
%%  Ein Beispiel der DANTE-Edition
%%  Mathematiksatz mit LaTeX
%%  3. Auflage
%%  Beispiel 09-25-1 auf Seite 206.
%%  Copyright (C) 2018 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[10pt]{screxa}
\pagestyle{empty}
\setlength\textwidth{170.40707pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\setcounter{section}{2}
%StartShownPreambleCommands
\usepackage{tcolorbox}
\newtcolorbox[auto counter,
  number within=section]{pabox}[2][]{%
  colback=red!5!white,colframe=red!75!black,
  fonttitle=\bfseries,title=Satz \thetcbcounter: #2,#1}
%StopShownPreambleCommands
\begin{document}
\begin{pabox}[colback=yellow]{Pythagoras}
\[ \sin^2\alpha+\cos^2\alpha=1 \]
\end{pabox}
\end{document}