F.2 Maths
2008-05-11 11:55 pm
圖片參考：http://hk.geocities.com/kingtom1232008/Maths.bmp
In the figure, A, B and C are the centres of three equal circles which touch each other externally. ΔABC is an equilateral triangle of side 4 cm. D, E and F are the mid-points of AB, BC and CA respectively. Find the perimeter of the shaded region. (Give your answer correct to 3 significant figures.)
回答 (2)
2008-05-12 12:11 am
✔ 最佳答案
[2πr × (360﹣60)÷360 × 3] (4×3)= [2π(2) × 300÷360 × 3] (4×3)
= 43.4 cm (correct to 3 significant figures.)
2008-05-11 16:14:33 補充：
[2πr × (360﹣60)÷360 × 3] 加 (4×3)
= [2π(2) × 300÷360 × 3] 加 (4×3)
= 43.4 cm (correct to 3 significant figures.)
呢個先o岩...上面show 唔到個加號
參考: me
2008-05-12 2:18 am
2兀r[(360-60) / 360 ] 3
=2兀2[300/360]3
=2兀2 (2.5)
=31.4 ( cor . to 3 sig. fig. )
=2兀2[300/360]3
=2兀2 (2.5)
=31.4 ( cor . to 3 sig. fig. )
參考: me
收錄日期: 2021-04-23 17:53:58
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080511000051KK01576