Angle of Elevation: find the height of the tree

[Mathisconfusing101]

How would I find the angle of elevation?

 

[galactus]

You're paintin' with a broad brush there mathconfused.

Give an example of your quandary.

 

[Mathisconfusing101]

The angle of elevation from the top of the tree to a point 30 feet from its base is 25°. Find the height of the tree.

ugh.. i seriously have an issue with retaining information.... summer.. brain should not be activated.. lol

 

[tkhunny]

Angle of Elevation
Angle of Depression

These are ALWAYS measured from the horizontal. ALWAYS!!!!

If you've an angle of elevation from the top of the tree, the point in question must be ABOVE the top of the tree.

My first guess would be that the problem statement means the angle of elevation TO the top of the tree FROM the spot on the gound 30 ft from the base. That would be an entirely different problem.

 

[galactus]

I am assuming this is your scenario:

Use law of tangents.

 

[Mathisconfusing101]

o goodness... theres those tangents again... lovely.. ill go search through the other post and find that.. lol

 

[stapel]

galactus: I like your picture! :wink: :lol:

Eliz.

 

[Mathisconfusing101]

ugh ok. law of tangents.. opp over adj... got it..

so the adj is 30... and the opp is unknown...

so would i flip it around and make it 30 times the 25 degrees?

 

[jonboy]

Hey Mathisconfusing, did you ever get that calc fixed? You would not do what you said to find the measure of the opposite side. You should have your problem set up like this:

\(\displaystyle \L\bold Tan25=\frac{x}{30}\)

Now remember you gotta do the inverse Tan \(\displaystyle (Tan^{-1})\). I gave you this website for a reason http://wright.nasa.gov/airplane/trig.html because it has all the inverse Tan operations on there. Go to the bottom where it says Tan(x), find what \(\displaystyle Tan25\) equals and solve for \(\displaystyle x\) (the opposite side).

 

[skeeter]

if x is the height of the tree, then tan(25) = x/30

multiply both sides by 30 ...

x = 30tan(25)

I already told you how to set up your calculator in degree mode ... just type in the right side of the last equation on your home screen and press [enter] ... you'll get the value for x.[/tex]

 

[tkhunny]

Please don't forget that the problem statement is totally wrong if that drawing is correct. You should not be expected to provide correct translations of incorrect problem statements.

 

[galactus]

galactus: I like your picture! :wink: :lol:

Eliz.

Thanks, Stapel. Microsoft paint brings out my artistic muse......NOT!! :lol: .