如图,已知:D是△ABC中BC边上一点,E是AD上一点,EB=EC,∠ABE=∠ACE.求证:(1)∠BAE=∠CAE; (2

2025-04-26 16:21:01
推荐回答(2个)
回答1:

解答:证明:在△BEC中,
∵EB=EC,
∴∠EBC=∠ECB,
又∵∠ABE=∠ACE,
∴∠ABC=∠ACB,
∴AB=AC,
在△AEB和△ACE中,

AB=AC
AE=AE
BE=CE

∴△AEB≌△ACE(SSS)
∴∠BAE=∠CAE;
(2)由(1)知AB=AC,
△ABC为等腰三角形,
∵∠BAD=∠CAD,
∴AD⊥BC.

回答2:

(1)△ABE和△ACE因1边相等,1角相等再加1公共边而全等,所以 ∠BAE=∠CAE
(2)由△ABE全等于△ACE得AB=AC,另加1角相等再加1公共边,所以△ABD全等于△ACD,∠BDA=∠CDA=180/2=90,所以AD⊥BC