1.已知:在△ABC中,∠ACB=90°,AC=CB,AE垂直CB,BE交AC于D,AE=1/2BD求证:BE平分∠ABC2.已知:在△ABC中,∠ABC=2∠C,∠ABC的平分线与AD垂直垂足为D求证:AC=2BD3.已知:在△ABC中,AB=AC,∠A=90°,M是AC的中点,AE垂
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![1.已知:在△ABC中,∠ACB=90°,AC=CB,AE垂直CB,BE交AC于D,AE=1/2BD求证:BE平分∠ABC2.已知:在△ABC中,∠ABC=2∠C,∠ABC的平分线与AD垂直垂足为D求证:AC=2BD3.已知:在△ABC中,AB=AC,∠A=90°,M是AC的中点,AE垂](/uploads/image/z/5377178-2-8.jpg?t=1.%E5%B7%B2%E7%9F%A5%EF%BC%9A%E5%9C%A8%E2%96%B3ABC%E4%B8%AD%2C%E2%88%A0ACB%3D90%C2%B0%2CAC%3DCB%2CAE%E5%9E%82%E7%9B%B4CB%2CBE%E4%BA%A4AC%E4%BA%8ED%2CAE%3D1%2F2BD%E6%B1%82%E8%AF%81%EF%BC%9ABE%E5%B9%B3%E5%88%86%E2%88%A0ABC2.%E5%B7%B2%E7%9F%A5%EF%BC%9A%E5%9C%A8%E2%96%B3ABC%E4%B8%AD%2C%E2%88%A0ABC%3D2%E2%88%A0C%2C%E2%88%A0ABC%E7%9A%84%E5%B9%B3%E5%88%86%E7%BA%BF%E4%B8%8EAD%E5%9E%82%E7%9B%B4%E5%9E%82%E8%B6%B3%E4%B8%BAD%E6%B1%82%E8%AF%81%EF%BC%9AAC%3D2BD3.%E5%B7%B2%E7%9F%A5%EF%BC%9A%E5%9C%A8%E2%96%B3ABC%E4%B8%AD%2CAB%3DAC%2C%E2%88%A0A%3D90%C2%B0%2CM%E6%98%AFAC%E7%9A%84%E4%B8%AD%E7%82%B9%2CAE%E5%9E%82)
1.已知:在△ABC中,∠ACB=90°,AC=CB,AE垂直CB,BE交AC于D,AE=1/2BD求证:BE平分∠ABC2.已知:在△ABC中,∠ABC=2∠C,∠ABC的平分线与AD垂直垂足为D求证:AC=2BD3.已知:在△ABC中,AB=AC,∠A=90°,M是AC的中点,AE垂
1.已知:在△ABC中,∠ACB=90°,AC=CB,AE垂直CB,BE交AC于D,AE=1/2BD
求证:BE平分∠ABC
2.已知:在△ABC中,∠ABC=2∠C,∠ABC的平分线与AD垂直垂足为D
求证:AC=2BD
3.已知:在△ABC中,AB=AC,∠A=90°,M是AC的中点,AE垂直BM于E,延长AE交BC于D
求证:∠AMB=∠CMD
4.已知:△ABD是等边三角形,△ABC是等腰直角三角形,其中AC=BC,∠ACB=90°,过D向AC的延长线作垂线,垂足为E
(1)如图,若△ABC在△ABD内,求证:DE=CE
(2)如图,若△ABC在△ADB外,问上述结论是否成立,若成立,给予证明,若不成立,说明理由.
图片点击查看原图啊..... 题应该没问题....
1.已知:在△ABC中,∠ACB=90°,AC=CB,AE垂直CB,BE交AC于D,AE=1/2BD求证:BE平分∠ABC2.已知:在△ABC中,∠ABC=2∠C,∠ABC的平分线与AD垂直垂足为D求证:AC=2BD3.已知:在△ABC中,AB=AC,∠A=90°,M是AC的中点,AE垂
第一题:
∵<C=<AEB=RT<(垂直的意义)
又∵<ADE=<CDB(对顶角相等)
∴<ADE=<CDB(三角巷内角和为180)
又∵AC=CB
∴<CAB=<ABC=45度
∴设<CDB=X,则<EBD为90-X,<ABE为X-45
又∵<EAD=<EBC
∴90+X-45+X-45+45=180
X=67.5
∴<ABE=67.5-45=22.5
∴<EBC=45-22.5=22.5
∴<ABE=<EBC=22.5
∴BE平分<ABC
题有问题!
图能大点儿吗?