A flagpole 20 m high stands on top of a tower which is 100 m high.

[Stein]

Application of Double Angles (Addition Formulas): A flagpole 20 m high stands on top of a tower which is 100 m high. At what distance from the base of the tower will the flagpole subtended an angle of 4 degrees? Assume height of instrument to be 4m. Answer: 46.493 m

I need help!!! Please show me a detailed solution to this problem. Thanks.

 

[Deleted member 4993]

A flagpole 20 m high stands on top of a tower which is 100 m high. At what distance from the base of the tower will the flagpole subtended an angle of 4 degrees? Assume height of instrument to be 4m. Answer: 46.493 m

I need help!!! Please show me a detailed solution to this problem. Thanks.

You have posted five problems without showing a line of work!

To start off, draw a sketch.

Please share your work with us ...

If you are stuck at the beginning tell us and we'll start with the definitions.

You need to read the rules of this forum. Please read the post titled "Read before Posting" at the following URL:

http://www.freemathhelp.com/forum/th...Before-Posting

 

[Stein]

You have posted five problems without showing a line of work!

To start off, draw a sketch.

Please share your work with us ...

If you are stuck at the beginning tell us and we'll start with the definitions.

You need to read the rules of this forum. Please read the post titled "Read before Posting" at the following URL:

http://www.freemathhelp.com/forum/th...Before-Posting

Forgive my ignorance, Mr. Khan. I'm desperate that's why I hurriedly posted the problem without reading the rules.
By the way, I'm a college freshman and we're currently in the application of double angle identities.

To start off,

Its obvious that the flagpole is on top of the tower. I'm just confused with the word "subtended". As well as, the statement "Assume the height of instrument to be 4 m". I can't picture out the drawing itself. Our professor taught us the double angle identities and provided some basic examples. Afterwards, this homework came out of nowhere like its really complicated. Please help me, Mr.Khan. Sorry for the grammatical error, I'm from the Philippines I'm just a trying hard when it comes to English language.

 

[Stein]

mr. khan. what will be your advice to me regarding this problem? i'm confused with the problem itself i can't picture out the drawing and the "assume height of instrument" doesn't ring a bell to me. please help me asap. thanks mr.khan i appreciate your help

 

[Ishuda]

Application of Double Angles (Addition Formulas): A flagpole 20 m high stands on top of a tower which is 100 m high. At what distance from the base of the tower will the flagpole subtended an angle of 4 degrees?

That means given a line segment connecting the top of the flagpole and the measuring point and another line parallel to the flat ground going through the measuring point, the angle between the two is 4 degrees. See below

Assume height of instrument to be 4m. ...

This means the height of the measuring point is 4m above the flat ground.

 

[Deleted member 4993]

Application of Double Angles (Addition Formulas): A flagpole 20 m high stands on top of a tower which is 100 m high. At what distance from the base of the tower will the flagpole subtended an angle of 4 degrees? Assume height of instrument to be 4m. Answer: 46.493 m

I need help!!! Please show me a detailed solution to this problem. Thanks.

It is the angle subtended by the flagpole is 4° - not the whole 116 m length.

Denis and Ishuda - to the corner....

Let the distance of the instrument from the base of the tower = d

Let the angle subtended by the structure (tower+pole) = Θ → tan(Θ) = 116/d

Let the angle subtended by the tower = Φ → tan(Φ) = 96/d

tan(Θ-Φ) = (20/d)/(1+11136/d²) = tan (4°) =0.069927

Now solve for 'd'

 

[Ishuda]

...

Denis and Ishuda - to the corner....

...

Oh well, 'live and learn' or 'learn something new each day and you will live forever'

 

[Stein]

Thank you again Mr. Khan. You're a big help!!! I finally solved it.

I continue from where you stop then,
I get this... 0.070(d)^2 - 20d + 779.52 = 0 so i used quadratic equation and i get 46.571m which is the correct answer!