∵CE＝3㎝,AB＝8㎝∴DE＝EF＝5㎝∵EF²＝CE²＋CF²∴CF＝4㎝∴S△ECF＝6㎝²∵∠AFE＝90°∴∠AFB＋∠CFE＝90°∵∠AFB＋∠BAF＝90°∴∠BAF＝∠CFE又∵∠B＝∠C＝90°∴△ABF∽△FCE∴S△ABF:S△F...