size(7cm,0); pair z1=(1,-0.25); pair v1=dir(45); pair z2=-z1; pair v2=0.75*dir(260); pair z3=(z1.x,-3); // A centered random number real crand() {return unitrand()-0.5;} guide g; pair lastz; for(int i=0; i < 60; ++i) { pair z=0.75*lastz+(crand(),crand()); g=g..2.5*z; lastz=z; } g=shift(0,-.5)*g..cycle; draw(g,gray(0.7)); draw("$r$",z1--z2,RightSide,red,Arrows,DotMargins); draw(z1--z1+v1,Arrow); draw(z2--z2+v2,Arrow); draw(z3--z3+v1-v2,green,Arrow); dot("1",z1,S,blue); dot("2",z2,NW,blue);