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三角形ABC中,
1. Show: cosA+ cosB+ cosC > 1.
2. a*cosA = b*cosB, which triangle?
3. Length(AB)=4, L(BC)=2*squr(3), the max of angle A ?
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三角形ABC中,
1. Show: cosA+ cosB+ cosC > 1.
2. a*cosA = b*cosB, which triangle?
3. Length(AB)=4, L(BC)=2*squr(3), the max of angle A ?