如题所述
16: 解:(1)证明.∵四边形ABCD是菱形,∴AD∥BC.∴∠1=∠2,又∵∠B=∠AED,∴△ABE∽△DEA.(2)∵△ABE∽△DEA,∴=,∴AE•DE=AB•DA.∵四边形ABCD是菱形,AB=4,∴AB=DA=4.∴AE•DE=AB2=16.