来自贝绍轶的问题
如图,已知在△ABC中,AD是内角平分线,点E在AC边上,且∠AED=∠ADB.求证:(1)△ABD∽△ADE;(2)AD2=AB•AE.
如图,已知在△ABC中,AD是内角平分线,点E在AC边上,且∠AED=∠ADB.
求证:(1)△ABD∽△ADE;(2)AD2=AB•AE.
1回答
2020-05-1301:49
如图,已知在△ABC中,AD是内角平分线,点E在AC边上,且∠AED=∠ADB.求证:(1)△ABD∽△ADE;(2)AD2=AB•AE.
如图,已知在△ABC中,AD是内角平分线,点E在AC边上,且∠AED=∠ADB.
求证:(1)△ABD∽△ADE;(2)AD2=AB•AE.
证明:(1)∵AD是内角平分线,
∴∠BAD=∠DAE,
∵∠AED=∠ADB,
∴△ABD∽△ADE.
(2)∵△ABD∽△ADE,
∴AD:AE=AB:AD,
∴AD2=AB•AE.