\documentclass{RetoPSTricks}

\begin{document}

\begin{pspicture*}(-0.13,-0.12)(1.13,1.13)
  \pstGeonode[PointName=none,PointSymbol=none]
  (0,0){A}
  (0,1){B}
  (1,1){C}
  (1,0){D}
  (0.41,1){P}
  \pstInterLL[PointName=none,PointSymbol=none]{A}{P}{B}{D}{E}
  \pspolygon[fillcolor=verdeodi,fillstyle=solid,opacity=0.15](B)(D)(A)(P)
  \pspolygon(A)(B)(C)(D)
  \rput(A){\psdot(0,0)\uput{0.6ex}[-135](0,0){\(A\)}}
  \rput(B){\psdot(0,0)\uput{0.6ex}[135](0,0){\(B\)}}
  \rput(C){\psdot(0,0)\uput{0.6ex}[45](0,0){\(C\)}}
  \rput(D){\psdot(0,0)\uput{0.6ex}[-45](0,0){\(D\)}}
  \rput(P){\psdot(0,0)\uput{0.6ex}[90](0,0){\(P\)}}
  \rput(E){\psdot(0,0)\uput{0.6ex}[20](0,0){\(E\)}}
\end{pspicture*}


\end{document}