\subsection{Positions relatives de deux plans}

\begin{propriete}
\begin{tableau}[L]{\linewidth}{3}{>{\centering}m{3.98cm}}
 \hline
 $(\mathcal P)$ et  $(\mathcal P')$ sont  strictement parallèles &  $(\mathcal P)$ et  $(\mathcal P')$ sont confondus &  $(\mathcal P)$ et  $(\mathcal P')$ sont sécants en $(d)$\\\hline
\begin{tikzpicture}[general, scale=0.25]
%\clip (-2.5,-0.6) rectangle (7.6,6.8);
\draw[color=G2, fill=G4] (-4,3)--(4.5,3)--(7.5,6.5)--(-0.5,6.5)--cycle;
\draw[color=H1prime, fill=H4] (-4,-1.5)--(4.5,-1.5)--(7.5,2.5)--(-0.5,2.5)--cycle;
\draw (0,0)--(4,0)--(4,4)--(0,4)--cycle;  
\draw (0,4)--(2,6)--(6,6)--(4,4);
\draw (6,6)--(6,2)--(4,0);
\draw[dashed] (0,0)--(2,2)--(6,2);
\draw[dashed] (2,2)--(2,6);
\draw (0.25,4) node[below, left, color=G2] {{\boldmath $(\mathcal P')$}};
\draw (0.25,-1) node[below, left, color=H1prime] {{\boldmath $(\mathcal P)$}};
\end{tikzpicture}&
\begin{tikzpicture}[general, scale=0.25]
\clip (-7.5,-3.5) rectangle (8.5,6.5);
\draw[color=G2, fill=G4] (-7,-3)--(3,-3)--(8,3)--(-2,3)--cycle;
\draw[color=H1prime, fill=H4] (-3,-1.5)--(3.5,-1.5)--(7,2.5)--(0.5,2.5)--cycle;
\draw (0,0)--(4,0)--(4,4)--(0,4)--cycle;  
\draw (0,4)--(2,6)--(6,6)--(4,4);
\draw (6,6)--(6,2)--(4,0);
\draw[dashed] (0,0)--(2,2)--(6,2);
\draw[dashed] (2,2)--(2,6);
\draw (-5,-2.5) node[ color=G2] {{\boldmath $(\mathcal P')$}};
\draw (0.25,-1) node[below, left, color=H1prime] {{\boldmath $(\mathcal P)$}};
\end{tikzpicture}&
\begin{tikzpicture}[general, scale=0.25]
\draw[color=H1prime, fill=H4] (-6,-2)--(7,-2)--(11,2)--(-2,2)--cycle;
\draw[color=G2, fill=G4] (-6,7)--(6,7)--(11,2)--(-2,2)--cycle;
\draw (0,0)--(4,0)--(4,4)--(0,4)--cycle;  
\draw[dashed] (0,4)--(2,6)--(6,6)--(4,4);
\draw (6,2)--(4,0);
\draw[dashed] (0,0)--(2,2)--(6,2)-- (6,6);
\draw[dashed] (2,2)--(2,6);
\draw[color=G1,  epais] (6,2)--(4,4)--(0,4);
\draw[color=G1,  epais, dashed] (0,4)--(2,2);
\draw[color=C1,  epais] (-3,2)--(11.2,2);
\draw (6,-1.2) node[ color=H1prime] {{\boldmath $(\mathcal P)$}};
\draw (-2,5) node[color=G2] {{\boldmath $(\mathcal P')$}};
\draw (-4,2) node[color=C2] {{\boldmath $(d)$}};
\end{tikzpicture}\\\hline
\end{tableau}
\begin{itemize}
 \item Un plan coupe deux plans parallèles suivant deux droites parallèles.
 \item Deux plans sont parallèles si et seulement si deux droites sécantes de l'un sont\\ respectivement parallèles à deux droites sécantes de l'autre. 
\end{itemize}
\end{propriete}
\vspace{-0.3em}
\begin{remarque} Deux plans confondus sont considérés comme parallèles.
\end{remarque}
