how to find the angle and length?

2007-08-27 5:49 am

回答 (1)

2007-08-27 6:20 am
✔ 最佳答案
把個 cone 展開係個 sector with radius 9 cm and arc length (3 pi) cm
最短距離咪 arc 兩端既直線長度,
先搵 sector 既角 = (3 pi) / 9 = pi/3 radian
一半係 pi/6 radian
arc 兩端既直線長度 = (2)(9) sin(pi/6) = 9 cm
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呢條比 d 時間,未諗到


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