%%%%%%%%%%%%%%ex21
\begin{exercice}Même consigne qu'au \RefExercice{2G2_base_pointX}
\begin{center}
 \begin{tikzpicture}[general]
  \quadrillageSeyes{(0,0)}{(5.6,4)}
  \draw[axe] (0,0.8)--(5.6,0.8);
  \draw[axe] (0.8,0)--(0.8,4);
  \foreach \x/\y/\N/\pos in {0.8/0.8/O/below left, 1.6/0.8/I/below, 0.8/1.6/J/left, 4.13/0.8/X/below} {\draw (\x,\y) node{\footnotesize $+$};\draw (\x,\y) node[\pos]{\footnotesize $\N$};}
  \draw[epais, color=F1, line cap= butt] (0.8,3.2)--(1.6,0.8)--(4.13,0.8);
   \draw (1.2,2) node[color=A1, rotate=31] {{\boldmath $\infty$}};
   \draw (2.865,0.8) node[color=A1, rotate=90] {{\boldmath $\infty$}};
 \end{tikzpicture}
\end{center}
\end{exercice}

