Question

2.3题怎么做啊

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Answer 1

∠ABC=2∠OBC,∠OBC=1/2∠ABC
∠ACB=2∠OCB,∠OCB=1/2∠ACB
∠OBC+∠OCB=1/2(∠ABC+∠ACB)
∠ABC+∠ACB=180-∠A=180-n
所以,∠OBC+∠OCB=1/2(180-n)=90-1/2*n
∠O=180-(∠OBC+∠OCB)=180-1/2(∠ABC+∠ACB)=180-(90-1/2*n)=90+1/2*n
即有,∠O=90+1/2*n
2)∠O1BC+∠O1CB=1/3(180-n)=60-1/3*n
或∠O2BC+∠O2CB=2/3(180-n)=120-1/3*n
∠O2=180-(∠O1BC+∠O1CB)=180-1/3(∠ABC+∠ACB)=180-(60-1/3*n)=120+1/3*n
即有,∠O1=120+1/3*n
∠O1=180-(∠O1BC+∠O1CB)=180-1/3(∠ABC+∠ACB)=180-(120-1/3*n)=60+1/3*n
∠O2=60+1/3*n
所以上,∠O2=60+1/3*n,∠O1=120+1/3*n
3)∠O(n-1)=(n-2)/(n-1)*180+n/(n-1)或∠O(n-1)=1/(n-1)*180+n/(n-1)

Answer 2

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