∵BE²=EF×EA∴BE/EF=EA/BE∵∠BEF=∠AEB∴△BEF ∽△AEB∴ ∠EBF=∠EAB∵AD∥BC∴∠EBF=∠ADB∴∠EAB=∠ADB∵∠ABF=∠DBA∴△ABF∽△DBA∴AB/BD=BF/AB∴AB²=BF×BD
ぇ锛屼篃涓嶈兘鐢ㄥ姏椤讹紝濂充汉鏄 嚜宸辩殑锛岃嚜宸卞绩鐤笺 效叧阌 槸鎴戠殑涔熶笉鏄 緢澶э紝镐庝箞浼氲繖镙凤紵璇ユ 庝箞瑙e喅锛?
∵BE²=EF×EA∴BE/EF=EA/BE∵∠BEF=∠AEB∴△BEF ∽△AEB∴ ∠EBF=∠EAB∵AD∥BC∴∠EBF=∠ADB∴∠EAB=∠ADB∵∠ABF=∠DBA∴△ABF∽△DBA∴AB/BD=BF/AB∴AB²=BF×BD
ぇ锛屼篃涓嶈兘鐢ㄥ姏椤讹紝濂充汉鏄 嚜宸辩殑锛岃嚜宸卞绩鐤笺 效叧阌 槸鎴戠殑涔熶笉鏄 緢澶э紝镐庝箞浼氲繖镙凤紵璇ユ 庝箞瑙e喅锛?