FoldOutLine[{a_,b_}]:={{a,#},{b,#}}&[a+0.5(b-a)+{{0.,0.5},{-0.5,0.}}.(b-a)] NextStep[in_]:=Flatten[FoldOutLine/@in,1] lines={{{0.,0.},{1.,0.}}}; Graphics[Line/@Nest[NextStep,lines,11]]