Question

已知：如圖，AB⊥BE于點B，DE⊥BE于點E，F、C在BE上，AC、DF相交于點G，且AB＝DE，BF＝CE．
求證： GF＝GC．

Answer 1

證明: ∵AB⊥BE，DE⊥BE
∴ÐABC=ÐDEF=90°                         
∵BF＝CE
∴BC="EF                                   "
又∵AB＝DE                                
∴△ABC≌△DEF                              
∴ÐACB=ÐDFE                                
∴GF＝GC   

解析