import geometry;
import patterns;
size(7.5cm,0);

// On définit :
point pA=(2,2), pB=(3,1.5), pC=(1.5,-1);

line droite1=line(pA,pB);
segment bord1=segment(relpoint(droite1,-.5),relpoint(droite1,1.5));
path zonehachuree1=bord1.A--bord1.B--(bord1.B.x,bord1.A.y)--cycle;

line droite2=line(pB,pC);
segment bord2=segment(relpoint(droite2,-.2),relpoint(droite2,1.2));
path zonehachuree2=bord2.A--bord2.B--(bord2.A.x,bord2.B.y)--cycle;

// On trace :
show(currentcoordsys);
dot("A",pA,S);
dot("B",pB,W);
dot("C",pC,NW);
draw(droite1^^droite2,red);
add("hachure1",hatch(H=3mm,dir=NE,red));
fill(zonehachuree1,pattern("hachure1"));
add("hachure2",hatch(H=2mm,dir=NW,blue));
fill(zonehachuree2,pattern("hachure2"));

addMargins(.1cm,.1cm);