Question

平行四边形ABCD中,AB⊥AC,AC⊥DC,AD=BC,试说明（1）AB=CD（2）AD平行CB

Answer 1

1)AB^2=BC^2-AC^2=AD^2-AC^2=CD^2 ==> AB=CD

2)∠BAC=∠ACD=90°内错角相等,AD平行CB