@options;
repereortho(-0.5,10,-1,10);


@figure;

  O = point(0,0) {fixe,(-0.5,0),gras,noir};
  A = point(1,0) {fixe,(0,-0.8),gras,noir};
  d=demidroite(O,A){i};
  B = pointsur(d,3.3) {(0,-0.8),gras};
  F=point(0,3) {i};
  d1=demidroite(O,F){i};
  C = pointsur(d1,0.2) {(0,-0.6),gras};
  d2=droite(A,C) {sansnom,rouge};
  d3=parallele(d2,B) {sansnom,rouge};
  D=intersection(d3,d1) {(0,-0.6),gras,rouge};
 
  var a=OB ;
  var b=OC ;
  var c=OD ;
  texte1=texte(2,9,"OB = $a$"){dec2};
  texte2=texte(2,8.2,"OC = $b$"){dec2};
  texte3=texte(2,7.4,"OD = $c$"){dec2,rouge};
  texte=texte(2,10,"Bouger les points B ou C !"){noir};


@analyse;


@config;
couleurfonddessin=0xFFFFFF;