Ketinit(); Setparent(Cdyname()+"fig"); Setketcindyjs([]); forall(allpoints(), parse("p"+#.name+"=Ptpos(#);"); ); Addax(0); pD=pA+(pB-pA)+(pC-pA); Arrowdata("1",[pA,pB]); Arrowdata("2",[pA,pC]); Arrowdata("3",[pA,pD]); Listplot("1",[pC,pD,pB],["da"]); Pointdata("1",pD,["Size=3","Color=red"]); Letter([pD,"ne","D"]); Expr([(pA+pB)/2,"se","\vec{a}",(pA+pC)/2,"nw","\vec{b}"]); Expr([(pA+pD)/2,"se","\vec{a}+\vec{b}"]); Figpdf(); Windispg(); //Help("Arrow");