input geometriesyr16; figure(0,0,11u,8u); trace feuillet; pair A,B,C,D,E,F,G; A=u*(3.5,3.5); B=u*(6,6); C=u*(7,4); D=u*(0.5,1); E=u*(1.2,4); F=u*(7.5,1); G=u*(1,6.5); marque_p:="croix"; dotlabel.bot(btex $A$ etex,A); dotlabel.top(btex $B$ etex,B); dotlabel.lrt(btex $C$ etex,C); dotlabel.lrt(btex $D$ etex,F); dotlabel.top(btex $E$ etex,G); drawarrow D--E withpen pencircle scaled 1bp; label.lft(btex $\vec{u}$ etex,iso(D,E)); fin; end