圖片參考：http://imgcld.yimg.com/8/n/HA00510450/o/701104220046113873430060.jpg
Find the angle between the line DF and the plane ABFE.
更新1:
ㄥDGF=90°?
maths~maths~
2011-04-22 9:42 pm
圖片參考：http://imgcld.yimg.com/8/n/HA00510450/o/701104220046113873430060.jpg
Find the angle between the line DF and the plane ABFE.
回答 (2)
2011-04-22 10:13 pm
✔ 最佳答案
Let H be a point on AE such that DH 丄 AE.AE² = 8² + 14² - 2(8)(14) cos95°AE = 16.71894 cm△ADE = (1/2) (8) (14) sin95° = (1/2) (AE) (DH)(1/2) (8) (14) sin95° = (1/2) (16.71894) (DH)DH = 6.6735 cmLet θ be the angle between the line DF and the plane ABFE :sinθ = DH / DFsinθ = 6.6735 / √(12² + 14²)θ = 21.2°
2011-04-22 14:27:17 補充：
I think G is H ,
Yes , ㄥDGF=90°
2011-04-22 9:56 pm
22.8度????????
收錄日期: 2021-04-21 22:22:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110422000051KK00461