如图,△ABC中,DE∥BC,EF∥CD,△AEF∽△ACD,AF=4,AB=6,试求AD的长.
问题描述:
如图,△ABC中,DE∥BC,EF∥CD,△AEF∽△ACD,AF=4,AB=6,试求AD的长.
答
∵△AEF∽△ACD,
∴
=AF AD
,AE AC
∵DE∥BC,
∴△ADE∽△ABC,
∴
=AD AB
,AE AC
∴
=AF AD
,AD AB
∴
=4 AD
,AD 6
解得:AD=2
.
6