# Quadrilateral through the Four lines L1,L2,L3,L4 Quad:=proc(L1,L2,L3,L4): Pt (L1,L2) , Pt (L2,L3) , Pt (L3,L4) , Pt (L4,L1) : end:
Quad:=proc(L1,L2,L3,L4): Pt (L1,L2) , Pt (L2,L3) , Pt (L3,L4) , Pt (L4,L1) : end:
Pt (L1,L2) , Pt (L2,L3) , Pt (L3,L4) , Pt (L4,L1) : end:
end:
