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Real World Trig Problem

  1. May 27, 2007 #1
    This may be off topic, but alot of smart and practical people hang out here so maybe someone can help.

    I need to find the height of my chimny in my back yard. I'm not wild about heights, so I'd rather not get out a long tape measure and a longer ladder to climb to the top.

    All the word problems we did in high school trig gave us all the pieces. Let's say I find a point 20 feet from the base, the 20*tan(x) where x is the angle to the top, is the answer.

    How can I find the angle x, without purchasing some expensive surveying equipment?

    Is there a better way to find the height?

    The application is how height of an antenna I can attach to my chimney. The town says 40', so I need to know how high it is now, so I know how much mast to purchase. Also, when the inspector shows up, I need to prove that is isn't over 40 feet.

  2. jcsd
  3. May 27, 2007 #2


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  4. May 27, 2007 #3
    Excellent idea. I used a framing square from the shop and got 23.25 feet.


  5. May 28, 2007 #4


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    I'm a little leery of attaching antennas to chimneys.
    Chimneys deteriorate after a while.
    In any event, I had a rather expensive antenna AND the top of the double flue chimney hit the pavement after 5 years or so.
    The chimney itself was more like 25-30 years and looked fine when I put it up, but if you have any cracks in the top cap they go quickly after that.
    The mast on this was only about 4 or 5 feet, with the big antenna around 18" with a small one at the top.
    If you are going to 40' then you need to guy the mast, which means the chimney needs to be centrally located.
    Personally, I'd forget the chimney and go with a roof mount.
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