∵△BCF,△ACE,△ABD是等边三角形.∴∠BCF＝∠ACE ,∠FBC＝∠DBA∴∠BCF－∠ACF＝∠ACE－∠ACF即∠ACB＝∠ECF∠FBC－∠FBA＝∠DBA－∠FBA即∠ABC＝∠DBF在△ABC和△EFC中,∵ BC＝CF,AC＝CE,∠ACB＝∠ECF∴△ABC≌△E...