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[TowerTalk] Elementary question - trig formula

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Subject: [TowerTalk] Elementary question - trig formula
From: clewis@ro.com (Chuck Lewis)
Date: Thu, 25 Jun 1998 17:22:45 -0500
This is a test, right?

Pythagoras sez (from his grave): C^2 =A^2 + B^2 where C is the length of
your guy, A is the height at which you attach it to your tower, and B is
the distance out from the tower to the anchor (assuming level ground).

If I understand your question, you want to know C.

In your case, A = 45', B = 30', and C = the square root of
(30x30)+(45x45) = 54.1 feet. 
That's the end-to-end guy length, not counting extra for connections,
nor accounting for turnbuckles, anchor rods, etc.

On the other hand, if you were asking something else, then I'm stumped.
anyone? ANYONE?

Chuck, N4NM
Pythagoras: What a Guy! 

Thomas Johnson wrote:
> 
> OK...
> Now, If I need MORE Phillystran to complete one last leg of my tower, and my
> tower is 50Ft, and I want to guy it at 45 feet, and my Ground anchor is 30 
> feet
> from the base of the tower, how much phillystran will I need to complete the
> connection (I will add on the Few extra feet later for clamping)
> 
> Tom
> K9KJ
> 
> Chuck Lewis wrote:
> 
> > Yep. Similar triangles...it's just a simple proportion...no trig needed.
> >
> > B/(C+D) = ?/C     or,
> >
> > ? = C x B/(C+D)
> >
> > Example: If you have a 100' tower (C+D), and the guys are out 60' (B),
> >
> > the distance out from the tower (?) at 50 feet DOWN (C) is
> >
> > 50' x 60'/100'  =  30'
> >
> > Makes sense, huh? Just make sure you use the distance from the top down,
> > not the height of the (?). (Or redo the equation)
> >
> > Chuck, N4NM
> >
> > Pete Smith wrote:
> > >
> > > At the risk of getting into the dumb question territory:
> > >
> > > If you know how far from the base of your tower your guys attach (on flat
> > > ground), and you know how high they attach to the tower, then you should 
> > > be
> > > able readily to calculate how much turning radius inside the guys would
> > > exist at any given height on the tower.  Obviously, this would be useful
> > > for assessing a potential stack design.
> > >                                                  I
> > >                                                 /I
> > >                                         / I
> > >                                        /  I C
> > >                                       /   I
> > >                                      /----I
> > >                                     /  ?  I
> > >                                    /      I D
> > >                                   /       I
> > >                             -----/----B---I---------
> > >
> > > That is, if you know the lengths of B and C+D, then you ought to be able 
> > > to
> > > figure out what "?" is for any length of C.
> > >
> > > Unfortunately, I've forgotten virtually all the plane geometry and trig
> > > formulas I ever learned, and I didn't keep any high school math books.  I
> > > think the two triangles involved are called "similar triangles," but 
> > > that's
> > > as far as my memory goes.  Can anyone tell me offhand what the right
> > > formula is for this?  Once I have the fomula I can do the calculations, 
> > > but
> > > what to calculate?
> > >
> > > Thanks!
> > >
> > > 73,  Pete Smith N4ZR
> > > In wild, wonderful, fairly rare WEST Virginia
> > >
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