如图,在△ABC中,EF∥BC且EF=2/3,BC=2cm,△AEF的周长为10cm,求梯形BCFE的周长.
题目
答案
∵EF=
,BC=2,
∴
=
,
∵EF∥BC,
∴△AEF∽△ABC,
=
=
,
∴
=
,
∴△ABC周长=30(cm)
∴梯形BCFE的周长=△ABC的周长-△AEF的周长+2EF=30-10+
=21
(cm).
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