Question

8年级下册数学课本104页15题怎么做?

Answer 1

已知,DE⊥AG,BF∥DE,可得：BF⊥AG；

在△ABF和△DAE中,∠AFB = 90°= ∠DEA ,∠BAF = 90°-∠DAF = ∠ADE ,AB = DA ,

所以,△ABF ≌ △DAE ,

可得：BF = AE = AF-EF ,

所以,AF-BF = EF .