bob is and he likes watching tv very much错了- -平行四边形ABCD中,BG⊥CD,且AB=BG=BE,AE交BG于点F.(1)若AB=3,∠BAD=60°,求CE的长。(2)求证:AD=BF+CG

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bobisandhelikeswatchingtvverymuch错了--平行四边形ABCD中,BG⊥CD,且AB=BG=BE,AE交BG于点F.(1)若AB=3,∠BAD=60°,求CE的长。(2)

bob is and he likes watching tv very much错了- -平行四边形ABCD中,BG⊥CD,且AB=BG=BE,AE交BG于点F.(1)若AB=3,∠BAD=60°,求CE的长。(2)求证:AD=BF+CG
bob is and he likes watching tv very much
错了- -
平行四边形ABCD中,BG⊥CD,且AB=BG=BE,AE交BG于点F.
(1)若AB=3,∠BAD=60°,求CE的长。
(2)求证:AD=BF+CG

bob is and he likes watching tv very much错了- -平行四边形ABCD中,BG⊥CD,且AB=BG=BE,AE交BG于点F.(1)若AB=3,∠BAD=60°,求CE的长。(2)求证:AD=BF+CG
(1)AB=3,则BG=BE=3.
∠BAD=60°,则∠BCA=60
在直角三角形BGC中,∠C=60,直角边BG=3,不难得出BC=2√3
则CE=2√3-3
(2)做辅助线BP⊥AE,交点为E,计算角度关系,不难得出∠ABC=120 => ∠EAB=30 => ∠ABP=60 =>∠PBF=30
再来计算边,AB=3 得出BP=1.5,得出BF=√3
由上一问可知,CG=√3,BC=2√3
所以 BC=BF+CG
所以AD=BF+CG

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