%\parbox[b][18em][c]{0.45\linewidth}{Pour les exercices \RefQCM{TSG3_QCM_ps_debut} à \RefQCM{TSG3_QCM_ps_fin}, on considère le cube $ABCDEFGH$ d'arête 2 ci-contre.\\
% On note $I$ le milieu de $[HG]$, $K$ celui de $[BC]$ et $J$ le centre de la face $ADHE$.\\
% Lorsque cela sera nécessaire, on se placera dans le repère orthonormé $\left(A\,; \dfrac{1}{2}\vv{AB}, \dfrac{1}{2}\vv{AD}, \dfrac{1}{2}\vv{AE} \right)$.}
% \parbox[b][18em][t]{0.55\linewidth}{\begin{center}
% 	\def \dx {-0.4}
%	\begin{tikzpicture}[general, scale=3]
%	%points
%	\coordinate (D) at (0,0); \draw (D) node[left] {$D$};
%	\coordinate (A) at (\dx,-0.5); \draw (A) node[below left] {$A$};
%	\coordinate (B) at (1+\dx,-0.5); \draw (B) node[below] {$B$};
%	\coordinate (C) at (1,0); \draw (C) node[right] {$C$};
%	\coordinate (H) at (0,1); \draw (H) node[above left] {$H$};
%	\coordinate (E) at (\dx,0.5); \draw (E) node[left] {$E$};
%	\coordinate (F) at (1+\dx,0.5); \draw (F) node[right] {$F$};
%	\coordinate (G) at (1,1); \draw (G) node[above right] {$G$};
%	\coordinate (I) at (0.5,1); \draw (I) node[above] {$I$};
%			\draw (I) node {$\times$};
%	\coordinate (J) at (\dx/2,0.25); \draw (J) node[left] {$J$};
%			\draw (J) node {$\times$};
%	\coordinate (K) at (1+\dx/2,-0.25); \draw (K) node[right] {$K$};
%			\draw (K) node {$\times$};
%	%arêtes
%	\draw (E)--(A)--(B)--(C)--(G)--(F)--(B); \draw (F)--(E)--(H)--(G);
%	\draw[dashed] (D)--(A); \draw[dashed] (D)--(C); \draw[dashed] (D)--(H);
%	%segments
%	%\draw[dashed, color=C1] (J)--(I)--(B)--(J);
%	\end{tikzpicture}
%	 \end{center}}

\begin{exercice} $\vv{JB} \cdot \vv{JI} = $
   \begin{ChoixQCM}{3}
    \item $-4$
    \item 0
    \item 4
   \end{ChoixQCM}
   \begin{corrige}
    \reponseQCM{b}
   \end{corrige}
  \end{exercice}

