P.6 maths

2006-12-14 4:08 am
繩子長20m,繞一圓桶4次,餘下1.16m,問圓桶的半徑是多少?

(圓周率=3.14)

回答 (7)

2006-12-14 4:16 am
✔ 最佳答案
圓周: 2 x 3.14 x 半徑

4 x (2 x 3.14 x 半徑) + 1.16m = 20m

4 x (2 x 3.14 x 半徑) = 18.84m

(2 x 3.14 x 半徑) = 4.71

半徑 = 0.75m
參考: 自己呀
2006-12-14 10:17 pm
設r為圓桶的半徑

20 - 1.16 = 2r(3.14)
18.84 = 6.28r
r = 3

所以圓桶的半徑等於3m
2006-12-14 6:47 am
設圓桶的半徑是y m
   (20-1.16) 
 ------------
 (4)(2)(3.14)
  18.84
=-------         ←18.84同25.12約
 8(3.14)
 6
=-
 8
 3       /
=-m     / =0.75m     ←可用分數或小數
 4     /
參考: 個人意見
2006-12-14 4:26 am
計法:四個圈的圓周長除4除3.14再除2就會等於半徑

20-1.16=18.84(四個圈的圓周長)

18.84 / 4 = 4.71(一個圈的圓周長)

4.71 / 3.14 = 1.5(直徑)

1.5 / 2 =0.75m(半徑)
2006-12-14 4:25 am
條式:(20-1.16)÷4÷3.14÷2
半徑=0.75m
2006-12-14 4:16 am
0.75m

20=(2xr X3.14X4)+1.16
18.84=2Xr X3.14X4
r=0.75
參考: me
2006-12-14 4:14 am
半徑 =(20-1.16)/4(3.14)(2)
=18.84 / 8 (3.14)
=6/8
=0.75m


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