Question

如圖，MC∥AB，NC∥AB，則點M，C，N在同一條直線上，理由是　　　　　　．                 

                                                                         

Answer 1

經(jīng)過直線外一點，有且只有一條直線與這條直線平行　．                               

                                                                                                          

【考點】平行公理及推論．                                                                     

【分析】直接利用平行公理：經(jīng)過直線外一點，有且只有一條直線與這條直線平行，得出即可．                    

【解答】解：∵M(jìn)C∥AB，NC∥AB，∴點M，C，N在同一條直線上，                 

理由是：經(jīng)過直線外一點，有且只有一條 直線與這條直線平行．                  

故答案為：經(jīng)過直線外一點，有且只有一條 直線與這條直線平行．               

【點評】此題主要考查了平行公理，熟練掌握平行公理是解題關(guān)鍵．