It is known that in square ABCD, point E is the point above ad, BF bisects ∠ EBC, intersects DC at point F, and the proof is: be = AE + CF

It is known that in square ABCD, point E is the point above ad, BF bisects ∠ EBC, intersects DC at point F, and the proof is: be = AE + CF

As Ag = FC, Ba = BC, gab = FCB = 90, so AGB and BFC are congruent, so GBA = FBC, BGA = BFC, because AB / / CD, so ABF = BFC, get BGA = ABF, because BF bisects ∠ EBC, EBF = FBC, and GBA = FBC, EBF = GBA, so EBF + Abe = GBA + Abe, GBE = ABF, combined with BGA = ABF, get