题目在Rt△ABCRt\triangle ABCRt△ABC中,∠BAC=90∘\angle BAC=90^{\circ}∠BAC=90∘,DDD是BCBCBC的中点,EEE是ADADAD的中点,过点AAA作AFAFAF∥BCBCBC交BEBEBE的延长线于点FFF.(1)(1)(1)求证:△AEF\triangle AEF△AEF≌△DEB\triangle DEB△DEB;(2)(2)(2)证明四边形ADCFADCFADCF是菱形;(3)(3)(3)若AC=4AC=4AC=4,AB=5AB=5AB=5,求菱形ADCFADCFADCF的面积.知识点:平行四边形的判定章节:图形的性质 / 四边形