嗰答案係:6(a)618cm^2 (b)1670cm^2 8(a)2440cm^2 (b)6440cm^2
http://macao838.com/image/1202958103.jpg
更新1:
我想要詳細既steps啊!!!thx
急~~~數學問題(求積)
2008-02-16 6:43 pm
可否幫我計算第６，８題，因為我唔識做啊！！！ｔｈｘ！！
嗰答案係:6(a)618cm^2 (b)1670cm^2 8(a)2440cm^2 (b)6440cm^2
http://macao838.com/image/1202958103.jpg
嗰答案係:6(a)618cm^2 (b)1670cm^2 8(a)2440cm^2 (b)6440cm^2
http://macao838.com/image/1202958103.jpg
回答 (1)
2008-02-17 3:51 am
✔ 最佳答案
我用英文答,你自己轉番中文la.6.(a)VB^2=20^2+30^2 (Pyth.Thm.)
VB=36.1cm -----(sqrt1300)
VC=30^2+20^2
VC=36.1cm
BC=30^2+30^2
BC=42.4cm
s=(BC+VC+VB)/2
s=57.3
Area of VBC
=sqrt[57.3(57.3-36.1)(57.3-36.1)(57.3-42.4)]
=622cm^2
(b)Total surface area
=VBC+VAB+VAC+ABC
=622+(20*30/2)*2+30*30/2
=1672cm^2
8(a)VEFGB
=[sqrt(50^2+10^2)]*20/2*4+20*20
=2440cm^2
(b)Total area
=50*20*4+20*20*2-2440
=2360cm^2
你自己check下8(b),我唔太sure
收錄日期: 2021-05-02 16:50:31
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080216000051KK00977