Question

．如图，下列说法错误的是（　　）                                                       

                                                                     

A．若a∥b，b∥c，则a∥c                             B．若∠1=∠2，则a∥c           

C．若∠3=∠2，则b∥c                                   D．若∠3+∠5=180°，则a∥c         

Answer 1

C【考点】平行线的判定．                                                                      

【分析】根据平行线的判定进行判断即可．                                             

【解答】解：A、若a∥b，b∥c，则a∥c，利用了平行公理，正确；             

B、若∠1=∠2，则a∥c，利用了内错角相等，两直线平行，正确；                

C、∠3=∠2，不能判断b∥c，错误；                                                      

D、若∠3+∠5=180°，则a∥c，利用同旁内角互补，两直线平行，正确；                    

故选C．                                                                                            

【点评】此题考查平行线的判定，关键是根据几种平行线判定的方法进行分析．