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【OG20-P291-435题】
In the figure above, points A, B, C, D, and E lie on a line. A is on both circles, B is the center of the smaller circle, C is the center of the larger circle, Dis on the smaller circle, and Eis on the larger circle. What is the area of the region inside the larger circle and outside the smaller circle?
(1) AB = 3 and BC = 2
(2) CD = l and DE = 4
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(1)大圆半径=AB+BC=5;小圆半径=AB=3。因此,题目所问部分面积为=π52-π32=16π.
(2)大圆半径=CD+DE=5;小圆半径=AD/2=(AC+CD)/2=(CE+CD)/2=3。
题目讨论 (4条评论)

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冲他丫的
阿西巴 2可以推出小的直径 除以2就出来小r了
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0 回复 2021-10-15 23:14:20
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贾思敏
这个题只要知道大圆的半径和小圆的半径,就是充分的了 条件一比较好看出来 条件二:大圆半径=CD+DE=1+4=5,小圆半径=AD的一半=1/2*AD=1/2*(AE-DE)=1/2*(5x2-4)=1/2*6=3
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0 回复 2021-10-04 16:28:13
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emily666
第二个条件想半天。。
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0 回复 2020-03-19 14:37:35
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尹鹤
突然失了智
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0 回复 2019-04-24 15:47:13