@options;

@figure;
  A = point( -4 , 0.23 );
  B = point( 1.63 , 0.7 );
  sAB = segment( A , B );
  C = point( -2.07 , 5.7 );
  sBC = segment( B , C );
  sCA = segment( C , A );
  bissCAB = bissectrice( C , A , B )  { orange };
  bissABC = bissectrice( A , B , C )  { orange };
  J = intersection( bissABC , bissCAB )  { vertfonce };
  A' = projete( J , sAB );
  ceJA' = cercle( J , A' )  { vertfonce };