Math question.

[tanglediver]

I have a right triangle with angles of 90 degrees, 31 degrees and 59 degrees. I know the length of one side, the longer side of the right angle, it is 0.086".
How can I find the length of the other side of the right angle?

[Broccoli1]

http://www.mathsisfun.com/pythagoras.html

[DSW]

It can be done with basic trig functions.

Tan of an angle= opposite length / Adjacent length.
Sine of an angle= opposite length / Hypotenuse.
Cosine of an angle= Adjacent length / Hypotenuse.


So if the angle is 31deg, the adj side is the long one at 0.086

tan59= unknown length / 0.086

0.086* tan 59 = Unknown length.

I can't find my trig calculator right now or I would do the math for you.
As long as you know the angle and one length you can find any of the others on a right triangle.

Hope this helps.

[Brett]

0.05167

[tanglediver]

I knew I would end up with a headache!

I found .051 after googling this up...
http://www.mathopenref.com/righttriangle.html
...I knew there is a formula of some trigometric sort, but not which or how to use it.

Where is that "Bang Head Here" sign?

Thanks for the clues, for sure!!

[Magnetic_re]

2 2 2
A+B=C(longest side of triangle)

[wannabe_welder]

Originally Posted by Magnetic_re

2 2 2
A+B=C(longest side of triangle)

You need at least 2 sides for that to work.

[tanglediver]

http://i176.photobucket.com/albums/w...r/P4270011.jpg

Here is the drawing with the problem and the answer that I wrote in. Then I found the trig functions explained well enough in the "Machinery's Handbook", page 91 of the 27th edition, so that I could punch the numbers into my scientific calculator. I never took triggernometry!

[DesertRider33]

Queen SohCahToa

[William McCormick Jr]

Originally Posted by tanglediver

I have a right triangle with angles of 90 degrees, 31 degrees and 59 degrees. I know the length of one side, the longer side of the right angle, it is 0.086".
How can I find the length of the other side of the right angle?

What angle is using the known side as one ray from its vertex?


Sincerely,


William McCormick

[dabar39]

Here's a real simple and easy way to figure out your math problem with out a lot of math involved. Dave

This was done real quick on scrap paper as an example, to make it work you must use a ruler and protractor!

[Brett]

Originally Posted by William McCormick Jr

What angle is using the known side as one ray from its vertex?


Sincerely,


William McCormick

Two are William,
The 90° and the 31°

[tanglediver]

Originally Posted by dabar39

Here's a real simple and easy way to figure out your math problem with out a lot of math involved. Dave

This was done real quick on scrap paper as an example, to make it work you must use a ruler and protractor!

Dude, when was the last time you took an I.Q. test? That is sheer genius!

[dabar39]

Originally Posted by tanglediver

Dude, when was the last time you took an I.Q. test? That is sheer genius!

No genius here, just had to improvise out in the field many, many times. Dave

[William McCormick Jr]

Originally Posted by Brett

Two are William,
The 90° and the 31°

The Cosine of Angle 31 is 0.8572 It is in a table in a book under 31 degrees cosine.

Hypotenuse = The side you know, 0.086 divided by 0.8572 =0.10032664489034064395706952869809


Sincerely,


William McCormick

[William McCormick Jr]

Originally Posted by Brett

Two are William,
The 90° and the 31°

Here are the formulas. It is funny in this book they misprinted the book. And the tables for the angles are wrong.

This book clearly defines how to use the formulas though, and the angle values. I use another book or a calculator for the angle values.

http://www.Rockwelder.com/WeldingWeb...ctformulas.JPG

Sincerely,


William McCormick

[Tinbasher]

Two ways to do it using tangent function...if I am understanding your question correctly

[tanglediver]

Originally Posted by Tinbasher

Two ways to do it using tangent function...if I am understanding your question correctly

Attachment 19322

0.052 is correct!
William, I used a formula from that same list along with my calculator also. Once the data was input correctly, I got an answer that made sense.

[William McCormick Jr]

Originally Posted by tanglediver

0.052 is correct!
William, I used a formula from that same list along with my calculator also. Once the data was input correctly, I got an answer that made sense.

I used the formula to find the hypotenuse. I thought that was what you were looking for. Then I went back and reread it. And saw you wanted the smaller side.

I cannot figure triangles without a book or cheat sheet.

Sincerely,


William McCormick

[Donald Branscom]

Originally Posted by Magnetic_re

2 2 2
A+B=C(longest side of triangle)

Then devide by 2 to get the awnswer.

[Sandy]

Here are a few of the Alt/Numbers combo keys here.
Sometimes there are other combinations that will do the same things. Even just three digits.
Depends on which text type and bla bla yadda yadda.
Play around with them.

Hold the Alt key and hit these numbers on the Nums key pad for these;

0178 = ² squared
0179 = ³ cubed
0247 = ÷ divided by
0215 = × multiply by
0176 = ° degree, also 167, 248
0162 = ¢ cents, also 155

[smokeshow]

¼ ( 172 )
½ ( 171 )
¾ ( 0190 )
° ( 248 )
² ( 253 )
√ ( 251 )
± ( 241 )
≥ ( 242 )
≤ ( 243 )
+ ( 43 )
☺ ☻ ♥ ♦ ♣ ♠ • ◘ ○ ◙ ♂ ♀ ♪ ♫ ☼ ► ◄ ↕ ‼ ¶ LOL.. sorry I got carried away... I used to send alt messages to people as a coded messages... I won't get into all of that but I have used them way too much.. and a lot of them repeat several times... the only difference is how many numbers you have to put in...

[William McCormick Jr]

Originally Posted by Donald Branscom

Then devide by 2 to get the awnswer.

Are you saying AxA + BxB = CxC ?

The square root of AxA + BxB = the length of side C or the hypotenuse of the triangle.


Sincerely,


William McCormick

[TEK]

WOW....that sure went off on a tangent.......( i'm sorry, really, i am)

[Mondo]

The way I learned trigonometry in electronics school was to remember these relationships:

Square of the length of side A plus the square of the length of side B equals the square of the length of side C. This editor does not support superscript so I will post an image:

Next, a phoney Indian word:

Soh Cah Toa (say it like this: So C-ahhh Toe-a)

Sine = length of side Opposite the angle divided by length of the Hypotenuse
Cosine = length of the side Adjacent to the angle divided by the length of the Hypotenuse
Tangent = length of the side Opposite the angle divided by the length of the side Adjacent to the angle.


If you have any two values of either of the above items you can calculate all the others.
We needed to learn this to calculate things like RMS voltage and energy in AC circuits, and other esoteric things like plotting the load line of a Class A transistor amplifier. But the same formulae are handy for any carpenter, fabricator, or just about any other tradesman.