Math CE 2007 Q19 how to do it?

角DFC=角BFE (對頂角)
角FCD=角FEB (錯角,EB平行DC)
角FDC=角FBE (錯角,EB平行DC)
所以三角形FDC形相似三角形FBE (AAA)
因此得知
DF/FB=CF/FE
DF*FE=CF*FB
角DFE=角CFB (對頂角)
面積DEF=DF*FE*sin角DFE/2
面積CBF=CF*FB*sin角CFB/2
面積比 1:1

Area of EDC=Area of BDC
=>Area of EDF +Area of DFC = Area of BCF +Area of DFC
=>Area of EDF= are BCF

so Area of EDF : Area of BCF = 1 :1 (A)//