宝鸡市金台区2015-2016学年高一上期末数学试卷含答案解析  
3．在空间，下列说法正确的是（　　）                                                   
A．两组对边相等的四边形是平行四边形                                                  
B．四边相等的四边形是菱形                                                                    
C．平行于同一直线的两条直线平行                                                         
D．三点确定一个平面                                                                         
【考点】棱柱、棱锥、棱台的体积．                                                        
【专题】数形结合；分析法；空间位置关系与距离．                                       
【分析】逐项分析，举反例判断．                                                            
【解答】解：四边形可能是空间四边形，故A，B错误；                                
由平行公理可知C正确，                                                                         
当三点在同一直线上时，可以确定无数个平面，故D错误．                            
故选C．                                                                                             
【点评】本题考查了平面的基本性质，属于基础题．