题目内容
如图,已知四边形ABCD是等腰梯形,AB=DC,AD∥BC,PB=PC.求证:PA=PD.
如图,已知四边形AB∥CD是菱形,DE⊥AB,DF⊥BC.求证△ADE≌△CDF
如图,已知四边形AB∥CD是菱形,DE∥AB,DFBC.求证≌