Hello, r_maths!
Welcome aboard!
Code:
* C
* |
A * * |
| * * |
| * * | 5
4 | * * |
| * θ * |
B * - - - - * - - - - - - * D
6 E 3 :
Two telephone poles, AB and CD, are situated 9m apart.
They are held by wires that are fixed to the ground at E.
Calculate exact value of
We want to find which is in
Look at the upper portion of the diagram. Code:
* C
| 1
A *-----------------------+ F
| 9 |
| |
4 | | 4
| |
B * - - - - + - - - - - - * D
6 E 3 :
Draw
We have a right triangle with
. . Hence: .
Back to the original diagram . . .
We have with
Using the Law of Cosines, we have:
. .
Therefore: .