HELP!! Mathematical DUers!! I need a quick answer to a trig question

[loudsue]

I hope some mathematically O8) brilliant O8) DUer answers this SOON...I have to send the RF engineer an e-mail and tell her how high the existing antennas are! This is a work problem. It involves a cellular tower....obviously. And I don't remember any trig. PLEASE HELP!

If I'm standing 231' from the base of the tower, and my range-finder shoots a distance of 303' to the antennas I'm trying to find the height of on the tower.....how high on the tower are the antennas going straight up from the ground?? The tower, of course, is at a right angle to the ground....it isn't the Leaning Tower of Cingular. (Don't worry that I'm 5' tall....as I look through the range finder.)

Thanks in advance.....

Sue (feeling a little dumb....)

[Dookus]

1. 196 feet

[loudsue]

2. Dookus.....

:yourock::yourock::yourock::yourock::yourock:

THANK YOU SOOOO MUCH!!

I've been searching google for an hour and a half, and all I was getting was....confused!!

Thanks SO much....BIG HUG!!!:pals:

[ConcernedCanuk]

3. I think this is a trick - but 231+5+303 ?

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on second thought

231 + 303

because more than likely you used the rangefinder to determine both distances

- so maybe an extra foot from pointing the rangefinder up/down

so 535

(I still suspect a trick)

:dunce:

[Dookus]

5. the way I understand it....

she's standing 231 feet from the antenna. Her range finder shows 303 feet to the top of the towers.

So we have a right triangle where the height of the tower is A, the bottom side (her distance from the base) is B (231 ft) and the hypotenuse, or the distance between herself and the top of the antenna, C.

The pythagorean theorem says A^2 + B^2 = C^2


C^2= 91809 ft. Subtract B^2 (53361) and we're left with 38448. The square root of 38448 is 196.0816.

OR...

196^2 + 231^2 = 303^2

[ConcernedCanuk]

7. oh - I was thinking she was standing ON the tower

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231 feet from the ground - -

doh:silly:

[Systematic Chaos]

4. It's the Pythagorean Theorem....

a^2 + b^2 = c^2

So:

a^2 + 231^2 = 303^2

a^2 + 53361 = 91809

a^2 = 38448

a = sqrt(38448) = approx 196 feet

[TXlib]

17. Yup, that's what I was going to post.

[punpirate]

6. An RF engineer could figure this out...

... on his or her own. It's simple Pythagorean square law stuff(a2 + b2 = c2).

For what sort of idiots do you work?

Cheers.

[loudsue]

8. She's never seen the tower

I'm in the field, she's in the office. I have to tell her what's up there, and I don't want her to think I'm an idiot....even if that shoe might fit right now. She needs to know what heights are "free" for us to attach antennae, so she can see if the antennae will be at the right height to be able to "talk to" the antennae on the next tower down the road in the system. Height, coordinates, and power all have to figure in to whether or not the radio signals will reach, .....or whether we're all going to be dropping calls from one spot to the next.

(Sorry if I'm not explaining it well....I'm WAY sleep-deprived.)

"CAN YOU HEAR ME NOW???"

[ConcernedCanuk]

10. YES

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196.08161 FEET

take that!

:hi:

[punpirate]

11. She doesn't need to be in the field, if you give the figures you have....

She should be able to figure out the height from what you provide.

What you are actually saying is that your office engineer is incompetent, and you're expected to make up for her incompetence. Sorry, I can't help with that. As I said, it's a simple equation, which has been known for 1500 years. It's not your fault, I know. Why not supply this ditzy engineer with the actual height of the antenna tower (from construction data) and let her decide how high the antenna must be placed?

Cheers.

[Dookus]

12. relax

she didn't say the engineer couldn't figure it out. Loudsue said she just didn't want to look like a dork by not doing it herself. The engineer just wants to know the height of the antenna. Loudsue just wants to give the answer.

There are no idiots here.

[punpirate]

16. Ummm. There's an idiot here.

Isn't you. Isn't me. Isn't Loudsue. *smile*

And I am relaxed. I'm the one without a job, but offering an answer. *smile*

So much for a good liberal education. :P

[ConcernedCanuk]

9. ah ok - frigadeee - I haven't done that for, hmm DECADES !

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196.08161

:bounce:

[ConcernedCanuk]

13. oh, I did the "google" thing now, - here's a handy website for you

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Select on the "drop down" list

Then click on "Open Pop-up Menu"

[NoPasaran]

14. WooHoo! Pythagoras at dawn!

Don't forget to show your work for full credit.

[DarkPhenyx]

15. No cheating on your homework!

Now you must stand with your nose in the corner of the forum.

[Enraged_Ape]

18. Um, did you all add in the 5 feet for the height to range finder?

Wouldn't that make it closer to 201 feet than 196? One leg of your right triangle is actually 5 feet above the ground.