是不是這個三角形abc的三個頂點(diǎn)都在圓o上,ab為直徑 ==> ∠C = 90°；==>RtΔCAB∠CAB = 30° ==> BC = 1/2 *AB；AC = √3/2 *AB ∴ AB = AC/(√3/2) = 2√3 ；BC =1/2 *AB = √3 CD平分角ACB ==> AD：BD = AC：BC = ...CD平分角ACB ==> AD：BD = AC：BC = 3：√3 --- (1)
怎么得到的？？∵AB為直徑∴∠ADB=∠ACB=90°
∴AD：BD = AC：BC = 3：√3
求采納
如圖,△ABC的三個頂點(diǎn)都在○O上,AB為直徑,CD平分∠ACB,∠CAB=30°,求AB AD和BD 的長
如圖,△ABC的三個頂點(diǎn)都在○O上,AB為直徑,CD平分∠ACB,∠CAB=30°,求AB AD和BD 的長
數(shù)學(xué)人氣：219 ℃時間：2020-01-28 01:41:50
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