Tikz Grafik neben Text

\documentclass[headheight=19pt]{scrartcl}
%------------------------------------------------------------------------------
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage[ngerman]{babel}
\usepackage{amsmath}
\usepackage[thmmarks,amsmath]{ntheorem}
\usepackage[norndcorners,customcolors,nofill]{hf-tikz} 
\usepackage{tikz}
\usetikzlibrary{quotes,babel,angles}
%-------------------------------------------------------------------------------
\tikzstyle{mybox}=[draw=gray, fill=white!20, align=left,  text width = 0.9\linewidth]
\hfsetbordercolor{gray} 
%-------------------------------------------------------------------------------
\theoremstyle{break}
\theoremheaderfont{\sffamily\small\bfseries}
\theorembodyfont{\normalfont\small}
\theoremindent1em
\newtheorem{Bei}{Beispiel}
%------------------------------------------------------------------------------
\setkomafont{pageheadfoot}{\normalfont\sffamily\scriptsize}
\renewcommand*{\thesubsubsection}{\arabic{subsubsection}}
%------------------------------------------------------------------------------
\tikzset{
  winkel/.style={draw=gray,angle eccentricity=.6,angle radius=0.6cm},
  mybox/.style={draw=gray,fill=white,align=left,text width=.9\linewidth}
}
\newbox\mytikzbox 
\newcommand{\tikzBox}[2][\mytikzbox]{% 
   \sbox#1{\pgfinterruptpicture#2\endpgfinterruptpicture}}
%------------------------------------------------------------------------------
\usepackage{blindtext}% für Fülltext
\begin{document}

  \begin{Bei}
  \begin{minipage}{0.4\textwidth} 
    Dieser Text soll links vom Schaubild stehen.Allerdings ist der Abstand zum Theorem nicht hinreichend
    \end{minipage}
    \begin{minipage}{0.4\textwidth} 
    \begin{tikzpicture}
    \tikzBox{%
      \tikz[auto]
      \draw
        (3,0) coordinate[label=right:B] (B)
        -- node{$c$} 
        (0,0) coordinate[label=left:A] (A)
        -- node{$b$} 
        (3,2) coordinate[label=above right:C] (C)
        -- node{$a$} 
        cycle
        pic["$\alpha$", winkel]{angle=B--A--C}% Winkel bei Node A
        pic["$\cdot$", winkel]{angle=C--B--A}% Winkel bei Node B
        pic["$\gamma$", winkel]{angle=A--C--B}% Winkel bei Node C
      ;
    }
    \end{tikzpicture}
    \end{minipage}
  \end{Bei}

\end{document}