\PGset[0.8em]
\vspace{-1ex}
\begin{picture}(6,4.5)

\drawline(1,1)(6,1)(2,3.5)(1,1) % BCAB

\drawline(3.65,3.5)(6,3.5) % d

% D = 3.35, 1
% mAC = -0.625, mAB = 2.5
% e1: (y-3.5)/(Ex-2) = 2.5$
% e2: (y-3.5)/(Fx-2) = -0.625$
% e3: Ex-Fx = 2.35$

% [[y = 2.325, Ex = 3.88, Fx = 1.53]]
\dashline[80]{0.2}(1.53,2.325)(3.88,2.325)(3.35,1) % FED

\put( 1.7, 3.6){$\scriptstyle A$}
\put( 0.7, 0.2){$\scriptstyle B$}
\put( 5.4, 0.2){$\scriptstyle C$}
\put( 3.0, 0.2){$\scriptstyle D$}
\put( 4.0, 2.3){$\scriptstyle E$}
\put( 1.0, 2.3){$\scriptstyle F$}

\put( 4.5, 3.6){$\scriptstyle d$}


\end{picture}
\PGrestore