在2D空間裡，等邊三角形的一隻角是60度，即一點(360度)的1/6。那麼在3D空間裡，正四面體的一隻'3D角'佔一個'3D點'的多少？[舉例說，正立方體的一隻'3D角'佔一個'3D點'的1/8]
English version:
In a 2D plane, each angle of a equiangular triangle is 60 degrees, that is 1/6 of a point (360 degrees).Then in a 3D space, how many percentage does a '3D angle' of a tetrahedron occupy a '3D point'??[For example, a '3D angle' of a cube is 1/8 of a '3D point']
20 point數學問題!高手請來相救!
2011-07-22 2:54 am
回答 (3)
2011-07-25 11:28 pm
✔ 最佳答案
the answer is about 1/22check these:
http://en.wikipedia.org/wiki/Spherical_trigonometry
http://mathworld.wolfram.com/SphericalTriangle.html
2011-07-23 10:11 pm
this is exactly what i mean.i tried to get the answer in this way,but i failed.
2011-07-23 14:13:09 補充：
can u help me??
2011-07-23 14:15:34 補充：
actually im working on a super hard math Q these days,but i have to solve this very hard Q first.if u are interested on what im doing,u can email me and i will tell u.
2011-07-23 14:16:37 補充：
do i need integration to deal with this??
2011-07-23 14:13:09 補充：
can u help me??
2011-07-23 14:15:34 補充：
actually im working on a super hard math Q these days,but i have to solve this very hard Q first.if u are interested on what im doing,u can email me and i will tell u.
2011-07-23 14:16:37 補充：
do i need integration to deal with this??
2011-07-23 9:33 pm
是不是這個立体角投射到球面上的面積與球面面積之比?
這涉及球面三角學。
這涉及球面三角學。
收錄日期: 2021-04-13 18:06:34
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110721000051KK00936