數學問題:正20面體體積

👨🏻‍🏫 學術台數學

2008-03-23 1:45 am

如果一個正20面體的外接圓半徑為1,找正20面體體積?
如果一個正20面體的內接圓半徑為1,找正20面體體積?

最好有步驟

更新1:

上面是2條唔同的問題不是同一個正20面體

回答 (3)

2008-03-25 10:52 am

✔ 最佳答案

用http://zh.wikipedia.org/w/index.php?title=%E6%AD%A3%E5%A4%9A%E9%9D%A2%E9%AB%94&variant=zh-hk裡面的公式：

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron.jpg

其中a是指正多面體的邊長。

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron1.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron2.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron3.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron4.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron5.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron6.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron7.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron8.jpg

圖片參考：http://i212.photobucket.com/albums/cc82/doraemonpaul/yahoo_knowledge/regularicosahedron/regularicosahedron9.jpg

參考: http://zh.wikipedia.org/w/index.php?title=%E6%AD%A3%E5%A4%9A%E9%9D%A2%E9%AB%94&variant=zh-hk + my maths knowledge

👍 0 👎 0

2008-03-23 2:10 am

如果一個正20面體的外接圓半徑為1,找正20面體體積?
如果一個正20面體的內接圓半徑為1,找正20面體體積?

👍 0 👎 0

2008-03-23 1:48 am

根本不知正20面體是怎樣的, 可否晝出來看看?

Best regards,

Samson So

👍 0 👎 0

收錄日期: 2021-04-19 00:43:48
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080322000051KK02328

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