 \begin{exercice}
Même consigne qu'à l'exercice \RefExercice{2G3_E_construire_somme}.
\begin{colenumerate}{2}
 \item $\vv{BC}+\vv{CD}$
 \item $\vv{BA}+\vv{BC}$
\end{colenumerate}

   \begin{tikzpicture}[general]
\quadrillageSeyes{(0,0)}{(8,3.2)}
\foreach \x/\y/\N/\pos in {1.6/0/A/above,3.2/1.6/B/left,6.4/0.8/C/below,6.4/2.4/D/above}
{\pointGraphique{\x}{\y}{\N}{\pos}}
\end{tikzpicture}
\end{exercice}
   
