已知：如图,AB//CD,角BAE+角CDF=180度.求证：AE//DF.

已知：如图,AB//CD,角BAE+角CDF=180度.求证：AE//DF. 如图,已知AB‖CD,AE‖DF,求证∠BAE=∠CDF 如图已知AB‖CD,AE∥∠DF,求证∠BAE=∠CDF 如图,已知AB＝CD,DF＝BE,AF＝CE,求证:∠CDF. 已知:如图8,AB//CD,∠BAE+∠DCE=90° 求证：AE⊥CE 已知,如图,ab等于cd,ae等于cf,bf等于de.求证:1,三角形abe全等于三角形cdf,2,角bed等于角dfb 如图 已知AB=CD,AE=DF,CE=BF.求证：AF=DE 已知：如图,AB=CD,BC=DA,AE=CF.求证：DF=DE 已知:如图,AD=CD CE=BF DF=AE 求证AB‖DC 如图,已知ABⅡCD,OA=OD,AE=DF,求证：BEⅡCF. 如图,AB=CD,AE=DF,CE=BF,求证AE平行DF 如图,AB=CD,AE=DF,CE=BF,求证：AE平行DF