若△ABC∽△DEF,且∠A=∠E,AB=DF=6,BC=5,AC=4,则DE=_.
问题描述:
若△ABC∽△DEF,且∠A=∠E,AB=DF=6,BC=5,AC=4,则DE=______.
答
由△ABC∽△DEF,且∠A=∠E,AB=DF=6,BC=5,AC=4,
∴
=BC DF
或AB DE
=BC DF
,AC DE
代入得:DE=
或24 5
,36 5
故答案为:
或24 5
.36 5