\begin{exercice*}
  Compléter.
  \begin{enumerate}
  \item
    $\left(\vv{AB},\vv{AC}\right)+\left(\vv{AC},\vv{AD}\right)=...$
  \item
    $\left(\vv{AB},\vv{BC}\right)+\left(\vv{...C},\vv{A...}\right)=\left(\vv{AB},\vv{AD}\right)$
  \item
    $\left(\vv{AB},\vv{CB}\right)=\left(\vv{AB},\vv{A...}\right)+\left(\vv{AC},\vv{...B}\right)$
  % \item
  %   $\left(\vv{BC},\vv{AB}\right)=\left(\vv{BC},\vv{A...}\right)+\left(\vv{...C},\vv{AB}\right)$
  \end{enumerate}
\end{exercice*}
\begin{corrige}
  \begin{enumerate}
  \item $\left(\vv{AB},\vv{AD}\right)$
  \item $\left(\vv{AB},\vv{AD}\right)$
  \item $\left(\vv{AB},\vv{AC}\right)+\left(\vv{AC},\vv{CB}\right)$
  % \item
  %   $\left(\vv{BC},\vv{AB}\right)=\left(\vv{BC},\vv{AC}\right)+\left(\vv{AC},\vv{AB}\right)$
  \end{enumerate}
\end{corrige}
