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幼苗
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延长CD、BA,相交于点F.
在△BCD和△BFD中,∠BDC = 90°= ∠BDF ,BD为公共边,∠CBD = ∠FBD ,
所以,△BCD ≌ △BFD ,可得:CD = FD = (1/2)CF .
在△ACF和△ABE中,∠ACF = 90°-∠CFA = ∠ABE ,AC = AB ,∠CAF = 90°= ∠BAE ,
所以,△ACF ≌ △ABE ,可得:CF = BE ;
则有:CD = (1/2)CF = (1/2)BE .
1年前
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