连结EF,则EF‖AB,且EF=0.5AB,
又∵EF‖AB,∴△EFG∽△ABG,有GE:GA=GF:GB=EF:AB=1:2,
同理可证,DG:GC=1:2,
∴GE:GA=GF:GB=DG:GC=1:2