如图,AB是圆o的直径,CD是圆O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交圆O于G如图,AB是⊙O的直径,CD是⊙O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交
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![如图,AB是圆o的直径,CD是圆O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交圆O于G如图,AB是⊙O的直径,CD是⊙O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交](/uploads/image/z/3719627-35-7.jpg?t=%E5%A6%82%E5%9B%BE%2CAB%E6%98%AF%E5%9C%86o%E7%9A%84%E7%9B%B4%E5%BE%84%2CCD%E6%98%AF%E5%9C%86O%E7%9A%84%E5%88%87%E7%BA%BF%2C%E5%88%87%E7%82%B9%E4%B8%BAC.%E5%BB%B6%E9%95%BF%E7%BA%BFAB%E4%BA%A4CD%E4%B8%8EE%2C%E8%BF%9E%E6%8E%A5AC%2C%E5%81%9A%E2%88%A0DAC%3D%E2%88%A0ACD%2C%E5%81%9AAF%E2%8A%A5ED%E4%B8%8EF%2C%E4%BA%A4%E5%9C%86O%E4%BA%8EG%E5%A6%82%E5%9B%BE%2CAB%E6%98%AF%E2%8A%99O%E7%9A%84%E7%9B%B4%E5%BE%84%2CCD%E6%98%AF%E2%8A%99O%E7%9A%84%E5%88%87%E7%BA%BF%2C%E5%88%87%E7%82%B9%E4%B8%BAC.%E5%BB%B6%E9%95%BF%E7%BA%BFAB%E4%BA%A4CD%E4%B8%8EE%2C%E8%BF%9E%E6%8E%A5AC%2C%E5%81%9A%E2%88%A0DAC%3D%E2%88%A0ACD%2C%E5%81%9AAF%E2%8A%A5ED%E4%B8%8EF%2C%E4%BA%A4)
如图,AB是圆o的直径,CD是圆O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交圆O于G如图,AB是⊙O的直径,CD是⊙O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交
如图,AB是圆o的直径,CD是圆O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交圆O于G
如图,AB是⊙O的直径,CD是⊙O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交圆O于G
[1]求证:AD是圆O的切线(我已经证出来了)
[2]如果⊙O的半径=6,EC=8,求GF的长
如图,AB是圆o的直径,CD是圆O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交圆O于G如图,AB是⊙O的直径,CD是⊙O的切线,切点为C.延长线AB交CD与E,连接AC,做∠DAC=∠ACD,做AF⊥ED与F,交
EC^2 = EB*EA ==== EC^2 = EB(EB+AB) === 64 = EB^2 + 12EB === EB = 4
===AE = 16 ,OE = 10 === AF = AE*OC/OE = 48/5 ,EC = 64/5 ====CF = 24/5
CF^2 = FG*FA ===.
∵∠BCE=∠CAE ∠E=∠E
∴△BCE相似△AEC
∴EB/EC=EC/EA即EB/8=8/EB+12
∴EB=4
∴EO=10
AE=16
∵△EOC相似△EAF
∴OC/AF=EO/EA
∴AF=906
∴EC/EF=EO/EA
∴EC/EF=EO/EA
∴8/8+CF=10/16 ...
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∵∠BCE=∠CAE ∠E=∠E
∴△BCE相似△AEC
∴EB/EC=EC/EA即EB/8=8/EB+12
∴EB=4
∴EO=10
AE=16
∵△EOC相似△EAF
∴OC/AF=EO/EA
∴AF=906
∴EC/EF=EO/EA
∴EC/EF=EO/EA
∴8/8+CF=10/16 CF=4.8
∵∠CAF=∠GCF ∠AFC=∠GFC
∴△ACF相似△CGF
∴CF/AF=GF/CF
所以GF=2.4
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