\PGset[0.8em]
\begin{picture}(14,13)

% radius = 6
\drawline(13.0000,7.0000)(10.0006,12.1960)(4.0012,12.1960)(1.0006,7.0000)(3.9994,1.8040)(9.9988,1.8040)(13.0000,7.0000)

\dashline[80]{0.2}(7,7)(4, 1.804) % OA
\dashline[80]{0.2}(7,7)(10,1.804) % OB
\dashline[80]{0.2}(7,7)(13,7)     % OC
\dashline[80]{0.2}(7,7)(10, 12.196) % OD
\dashline[80]{0.2}(7,7)(4, 12.196)  % OE
\dashline[80]{0.2}(7,7)(1, 7)       % OF

\drawline(7,7)(7,1.804) % OM

\put( 3.9, 0.9){$\scriptstyle A$}
\put( 9.2, 0.9){$\scriptstyle B$}
\put(13.1, 6.7){$\scriptstyle C$}
\put( 9.2,12.3){$\scriptstyle D$}
\put( 3.9,12.3){$\scriptstyle E$}
\put( 0.3, 6.7){$\scriptstyle F$}
\put( 6.7, 7.4){$\scriptstyle O$}
\put( 6.5, 0.9){$\scriptstyle M$}

\end{picture}
\PGrestore