@options;
  repereortho(310,270,30,1,1){ 0 , moyen , noir , num1 ,i};

@figure;
  O = point( -0.57 , -0.33 );
  cerayO4 = cerclerayon( O , 4 );
  T2 = pointsur( cerayO4 , 133 );
  M = point( 0.46 , 4.93 )  { rond2 };
  dT2M = droite( T2 , M )  { noir };
  T1 = intersection( dT2M , cerayO4 , T2 );
  H = milieu( T2 , T1 )  { rouge , 2 , (-0.57,-0.67) };
  sHO = segment( H , O )  { rouge };