/* un triangle et ses hauteurs */

import math;
size(6cm,0);
// Tracé du triangle
pair A=0, B=(3,1), C=(1.5,3);
path p=A--B--C--cycle;
draw(p);
drawline(A,A+dir(90+degrees(B-C,false)),
         .5bp+red+dashed);
drawline(B,B+dir(90+degrees(A-C,false)),
         .5bp+blue+dashed);
drawline(C,C+dir(90+degrees(A-B,false)),
         .5bp+.5green+dashed);