Calculate some things about a tetrahedron

  • Thread starter Harmony
  • Start date
  • #1
203
0
Question Statement:
Each surface of a tetrahedron ABCD is an equilateral triangle with each side 2 units long. The midpoint of AB and CD are L and M respectively. Calculate, by giving your answers correct to 3 s.f. or to the nearest 0.1 degree,

a) The length of the perpendicular from A to the plane BCD
b) The angle between the surface ACD and BCD
c) Angle between AB and the plane BCD

My Attempt So Far :
I have solved part A and B. The only part that confuse me is part C.
My calculation :
let the angle between AB and the plane BCD be x.
The perpendicular distance from A to the plane BCD be p.
So sin x = p/AB = 1.63/2

But the answer given is x = 53.1 degree, which is slightly smaller than the answer I found.

Is the method I used wrong?
 

Answers and Replies

  • #2
397
0
Just looking quickly the answer you have may be less due to rounding error. How much less is your answer than the answer given in the book?
 
  • #3
203
0
1 degree. The answer given is 53.1 degree, wheres mine is about 54 degrees.
 

Related Threads on Calculate some things about a tetrahedron

  • Last Post
Replies
10
Views
3K
  • Last Post
Replies
4
Views
7K
Replies
9
Views
1K
  • Last Post
Replies
3
Views
3K
  • Last Post
Replies
9
Views
1K
Replies
11
Views
2K
Replies
13
Views
4K
Replies
4
Views
2K
Replies
1
Views
5K
Replies
3
Views
2K
Top