@options;
 repereortho(183,458,15,1,1){ 0 , moyen , grisfonce , num1 };

@figure;
 A = point( -10 , 0 )  { noir , fixe };
 B = point( 0 , 0 )  { noir , fixe };
 sAB = segment( A , B )  { i };
 M = pointsur( sAB , 0.71 )  { rouge , gras };
 daAsAB = droiteangle( A , sAB , 60 )  { i };
 daMsAB = droiteangle( M , sAB , 60 )  { indirect , i };
 N = intersection( daMsAB , daAsAB )  { noir , (-0.3,-0.87) };
 perpBsAB = perpendiculaire( B , sAB )  { i };
 perpMsAB = perpendiculaire( M , sAB )  { i };
 r_M = rotation( M , 90 )  { noir };
 D = image( r_M , B )  { noir , (-0.27,-0.8) };
 perpDperpMsAB = perpendiculaire( D , perpMsAB )  { i };
 C = intersection( perpBsAB , perpDperpMsAB )  { noir , (-0.27,-0.83) };
 polyNMAN = polygone( N , M , A  )  { 3 };
 polyMBCD = polygone( M , B , C , D  )  { vert , 3 };
 p_disAB = milieu( A , B )  { i };
 t_disAB = texte( p_disAB ,"AB=#AB=#cm")  { noir , (-1.6,1.4) , dec2 ,
car+3 , gras };
 sAN = segment( A , N )  { / };
 sNM = segment( N , M )  { / };
 sAM = segment( A , M )  { / };
 sMD = segment( M , D )  { vert , // };
 sDC = segment( D , C )  { vert , // };
 sCB = segment( C , B )  { vert , // };
 sMB = segment( M , B )  { vert , // };
 angleMDC = angle( M , D , C );
 angleMBC = angle( M , B , C );
 angleDMB = angle( D , M , B );
 angleDCB = angle( D , C , B );
 //fleche;
 var xA = abscisse(A) { -10 };
 var xAp1 = xA+1 { -9 };
 var xB = abscisse(B) { 0 };
 var xBm1 = xB-1 { -1 };
 E = point( xA , -1.1 )  { fixe , sansnom , i };
 F = point( xB , -1.1 )  { fixe , sansnom , i };
 sEF = segment( E , F )  { noir , 3 };
 G = point( xAp1 , -0.8 )  { fixe , sansnom , i };
 H = point( xAp1 , -1.4 )  { fixe , sansnom , i };
 J = point( xBm1 , -0.8 )  { fixe , sansnom , i };
 I = point( xBm1 , -1.4 )  { fixe , sansnom , i };
 sGE = segment( G , E )  { noir , 3 };
 sHE = segment( H , E )  { noir , 3 };
 sJF = segment( J , F )  { noir , 3 };
 sIF = segment( I , F )  { noir , 3 };
 pm_disAM = milieu( A , M )  { i };
 tm_disAM = texte( pm_disAM ,"#AM=#")  { rouge , dec2 , car+1 };
 var x = AM { 7.1 };
 var y1 = 3*AM { 21.3 };
 var y2 = 4*BM { 11.6 };
 periTri = point( x , y1 )  { trace };
 periCar = point( x , y2 )  { trace };