(2014?闸北区一模)如图,点G是Rt△ABC的重心,过点G作矩形GECF,当GF:GE=1:2时,则∠B的正切值为____

2025-02-26 02:53:54
推荐回答(1个)
回答1:

解:连接AG并延长交BC于点H,
∵点G是Rt△ABC的重心,
∴BH=CH,
AG
AH
=
2
3

∵GE∥BC,
∴△AGE∽△AHC,
GE
CH
=
AE
AC
=
2
3

设GE=2x,则CH=3x,BC=6x,
∵GF:GE=1:2,
∴GF=HF=x,
∵四边形GECF是矩形,
∴CE=GF=x,
∴AC=3CE=3x,
∴tan∠B=
AC
BC
=
3x
6x
=
1
2