AC = 11.3 cm, AG and CG = 10.6 cm respectively.
Angle AGC = 64.3 degree
Find the angle between the planes ACG and ABCD
Figure: http://img11.imageshack.us/img11/8167/maths18.jpg
更新1:
deathnotesimonxdd: Where is K?
F4 Maths 3-D problems
2010-03-17 2:25 am
The figure shows a rectangularblock of dimensions 8 cm x 8 cm x 7 cm.
AC = 11.3 cm, AG and CG = 10.6 cm respectively.
Angle AGC = 64.3 degree
Find the angle between the planes ACG and ABCD
Figure: http://img11.imageshack.us/img11/8167/maths18.jpg
AC = 11.3 cm, AG and CG = 10.6 cm respectively.
Angle AGC = 64.3 degree
Find the angle between the planes ACG and ABCD
Figure: http://img11.imageshack.us/img11/8167/maths18.jpg
回答 (2)
2010-03-17 3:44 am
✔ 最佳答案
Extand G to meet AC at K, such that KB perpendicular to BGAngle required is <BKG,
AC=√(2*8^2)
AC=8√2 cm
BK*AC = 8*8
BK = 8/√2 cm
tan<BKE = 7/(8/√2)
<BKE = 51.1deg (corr. to 3 sig. fig.)
Hence, the angle between the planes ACG and ABCD is 51.1 deg
2010-03-16 21:40:01 補充：
Extand G to meet AC at K, such that KB perpendicular to BG
2010-03-16 21:42:19 補充：
http://img267.imageshack.us/i/maths18.jpg/
參考: Hope can help you^^”
2010-03-17 3:39 am
51.0度~~~~~~~~~~~
收錄日期: 2021-04-23 20:40:35
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100316000051KK01083