S△AFG=S△GFE__________AG=GF(等高,等底)S△ADF=3△EDB__________AG=3EB(等高)AG=9 EB=4S△CBA=5S△CBD_________CA=5CD(等高)CA=12 CD=2.4 DA=9.6S△DEA=3S△DEF_________DA=3DF (等高)DA=9.6 DF=3.2 FA=6.4