Answer:
The height of first tree is
[ 5.5+18tan(50 degrees) ] ft. This is approximately 26.95 ft.
Angle of elevation from Jimmy's eyes to top of tree is arctan([20+18tan(50 degrees)] /18). This is approximately 66.53 degrees.
Explanation:
It would help you to draw a picture for both of these.
You have a person whose height is 5.5 ft and from there horizontal gaze they see a bird from a 50 degree angle of elevation. He is standing 18ft ftom the tree.
So we will first want to find the distance from his eyesight level to the top of the tree. We can do this using the tangent ratio since we have the opposite and adjacent measurements.
Let the distance from eyesight level to the top of the tree be r.
tan(50)=r/18
Multiply both sides by 18:
18tan(50)=r
Now the height of the tree is
[5.5+18tan(50 degrees)] ft.
Now if he is the middle of two trees, then he 18 ft from the 2nd tree.
Since he says the height is 20ft taller than the first tree then it's height is
[20+5.5+18tan(50 degrees)] ft.
Now since we want to find his angle of elevation to the top of the 2nd tree we need to take out his height given us the distance from his eyesight level to the top of the tree which is
[20+18tan(50 degrees)] ft..
So again we are using the tangent ratio.
Let this angle if elevation be P.
tan(P)=[20+18tan(50 degrees)] /18
Take arctan() of both sides:
P=arctan([20+18tan(50 degrees)] /18)