import geometry;

size(7.5cm);
line l1=line(1,0),l2=line(-.5,0);
triangle t=triangleabc(3,8,10,(5,2)),
         imt=scale(-1,l2,l1)*t; 
// tri=triangleabc(a=3,b=8,c=10,angle=0,A=(5,2));
// tri est un triangle ABC direct, tel que :
//                     A=(5,2), 
//                     (vec(i),vec(AB))=0,
//                     a=BC=3,b=AC=8,c=AB=10
		 
draw(l1,red);
draw(l2,blue);

show(t);
show("$A'$","$B'$","$C'$",imt);

draw(line(t.A,imt.A)^^line(t.B,imt.B)^^line(t.C,imt.C),dashed);

draw(segment(t.A,imt.A),1bp+red,StickIntervalMarker(2,1));
draw(segment(t.B,imt.B),1bp+blue,StickIntervalMarker(2,2));
draw(segment(t.C,imt.C),1bp+green,StickIntervalMarker(2,3));

addMargins(10mm,10mm);