simple trig help needed

[dodge man]

Unless I misread the post, tangent is not the correct function, but cosine is. I believe the correct formula is Cosine of 52=B/C This makes the cosine of 52=100/C which come out to 162.42

 

[k0ua]

Unless I misread the post, tangent is not the correct function, but cosine is. I believe the correct formula is Cosine of 52=B/C This makes the cosine of 52=100/C which come out to 162.42

He doesnt want to know the hypotenuse he wants to know the other square leg. so tan =opp/adj would be the correct do it all in one whack function I believe.

James K0UA

 

[lockhaven]

as I stated before if the actual dimensions are posted I will give him a drawing of the exact distance, he can even give me the difference between the height of one bank to another does not matter. I can even produce a 3d picture if that is what it takes. THIS IS FUN:laughing:

 

[MikeInEburg]

use the Pythagorean formula A2 + B2 =C2
so the formula you want is A squared = C squared - B squared you only need 2 parts of a right triangle to solve....

FYI - Pythagorean theorem only works with right triangles.
Mike.

 

[mbohuntr]

Ok, I see what he is doing, Pick a spot on this side of a stream. Look directly across at the opposite side at a tree. Tree is the angle point. Now walk 100' downstream and measure the angle to the tree. So, you will need The Tangent function. Tan (angle) = 100/(X)

Tan(angle)(X)= 100

X= 100/Tan(angle)

 

[TedBell]

Just curious, how does one compute the 52 degree angle out in the field? A big protractor or something?

 

[k0ua]

Just curious, how does one compute the 52 degree angle out in the field? A big protractor or something?

I would think a transit would be just the ticket, of course I guess you could build a big protractor.. another great way to find the distance accros that stream would be a nice lazer range finder:thumbsup:

James K0UA

 

[Depmandog]

A very inexpensive yet practical way to measure your creek: drill a hole in a baseball, insert a suitable length of non stretch cordage (will suggest a mason line for this...it will stretch, but not before it pulls the ball); tie a keeper knot into the ball thru a metal washer to keep from losing the ball.

Hold onto the very end of the cordage (might even tie a washer / knot on this end to keep from slipping through your grasp) lightly coil the rope in your non throwing hand, then toss the ball across the creek.

Pull ball slowly back to where you desire your starting measurement to be, and if you are standing where you want the ending measurement, slightly taut the line and mark with a piece of tape.

Pull the ball back across, stretch out your line, and the measure the cordage from the ball to your tape, and you have a decent measurement. Probably within a few inches of of the exact.

I happen to have a transit and a laser measuring device that would be the preferred method.

 

[kevincook]

This is that old indian phrase: soh cah toa

Sin=opposite/hypotenuse
Cos=adjavent/hypotenuse
Tan=opposite/adjacent

Probably not PC but that has always been how I remember it.

Kevin

 

[hosspuller]

try an old boy scout method... walk away from the point you're trying to cross. get a stick, sight along it from one crossing point to the other. Then, holding the sight point rotate it 180 degrees to the same side and mark the new point. Get a tape measure and measure the distances between the two sight points on your side of the creek. That's how long of a log you'll need to fell to span the creek. Easy and simple.

you can also use this meathod to pick the standing tree you'll need. :laughing: