\psset{xunit=1cm, yunit=1cm}
%\psframebox{
\begin{pspicture}(-0.5,-0.5)(5,2.1)
%\psgrid(0,0)(5,2)
	
%\begin{pspicture}(0,0)(12, 2)
\SpecialCoor
%\psline(0,0)(4,3)
\psline[linecolor=blue](0,0)(4;30.23)
%\psline[linecolor=blue](4;30.23|4.6295690655178304211198499881141,0)
\psline[linecolor=blue](0,0)(4.6295690655178304211198499881141,0)  %cos \alpha = b/c
\psline[linecolor=blue](4.6295690655178304211198499881141,0)(4;30.23)

\psarc(3.42,2){0.5cm}{210}{305}
\psarc(0,0){1cm}{0}{30.23}



\uput[r](0.5;20){$\alpha$}
\rput[c](3.35,1.7){\Huge{$\cdot$}}
\rput[c](2.3,-0.25){c}
\rput[c](4.3,1){a}
%\psarc(0,0){2.5cm}{19}{71}

%(2.3308602987736;59.77)
%3,9284742244794781932242365314914
%(0,0)(6;40)(2;10|6;40)%(4;40|0,0)
	%(0,0) (5;30.23) %Länge(Radius), Winkel
	% nächster Winkel wäre 59,77°
	
	%(!50 cos 4 mul 0)




%\rput[c](6,1.5){$\vec{e_1}=\left(1,0,\ldots,0\right)$\hspace{5mm}\ldots\hspace{5mm}$\vec{e_i}=\left(0,\ldots,1,\ldots,0\right)$\hspace{5mm}\ldots\hspace{5mm}$\vec{e_n}=\left(0,\ldots,0,1\right)$}
%\rput[c](6,1.5){\psframebox{$\cdot$}}
%\rput[c](4.3,1.5){\psframebox{$\vec{e_1}=\left(1,0,\ldots,0\right)$\hspace{5mm}\ldots\hspace{5mm}$\vec{e_i}=\left(0,\ldots,1,\ldots,0\right)$\hspace{5mm}\ldots\hspace{5mm}$\vec{e_n}=\left(0,\ldots,0,1\right)$}}
%\psline[arrows=->](7.9,0.5)(7.9,1.2)

%\psline[arrowlength=3, arrowinset=0.1, linecolor=red]{->}(6.37,0.5)(6.37,1.3)
%\rput[c](6.37,0.2){\color{red}{i. Koordinate}}

%\rput[c](0.5,0.5){.}
%\rput[c](12,2){.}

\end{pspicture}%}
%rput center --> Koordianten werden um die x-Koordinate ausgerichtet