@options;

@figure;
  A = point( -5.5 , -2.65 )  { (-0.37,-0.02) };
  B = point( 5 , -4.01 );
  C = point( -1.1 , 4.53 )  { (-0.02,-0.67) };
  sAB = segment( A , B );
  sBC = segment( B , C );
  sCA = segment( C , A );
  angleBAC = angle( B , A , C )  { rouge , plein50 };
  angleCBA = angle( C , B , A )  { vert , plein50 };
  angleACB = angle( A , C , B )  { plein50 };
  E = milieu( sCA )  { (-0.43,-0.67) };
  F = milieu( sBC )  { (0.08,-0.63) };
  sEF = segment( E , F )  { noir };
  s = reflexion( sEF );
  C' = image( s , C )  { noir , (-0.04,0.08) };
  H = projete( E , sAB )  { (-0.21,0.03) };
  D = projete( F , sAB );
  sEH = segment( E , H )  { noir };
  sFD = segment( F , D )  { noir };
  angleC'HE = angle( C' , H , E );
  angleC'DF = angle( C' , D , F );
  sEC' = segment( E , C' )  { rouge };
  sFC' = segment( F , C' );
  angleEC'A = angle( E , C' , A )  { rouge , plein50 };
  angleDC'F = angle( D , C' , F )  { vert , plein50 };
  angleFC'E = angle( F , C' , E )  { plein50 };
  sFB = segment( F , B )  { vertfonce };
  sEA = segment( E , A )  { rouge };