Right Triangle

[44MAG#1]

How does one find the unknown side of a right triangle?

Thanks

[Castaway]

Square the hypotenuse, square the known side. Subtract the difference. Take square root of the difference

[Winger Ed.]

I cheat and use a tape measure or ruler.:bigsmyl2:

[M-Tecs]

https://www.omnicalculator.com/math/right-triangle-side-angle

https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-solve-for-a-side/a/unknown-side-in-right-triangle-w-trig

[georgerkahn]

How does one find the unknown side of a right triangle?

Thanks

I have regularly employed "c-squared" = "a-squared" plus "b-squared". The ubiquitous classic right triangle is the "3-4-5", where one side's length is 3, the next is 4, and the long (aka hypotenuse) is 5. Assume you know the long side, which is "c", then c-squared is 5 times 5 = 25. One side we know to be 3, and 3-quared = 3 times 3 = 9. Simplifying this to determine the unknown side, then simply subtract the 9 from 25 which is 16. The square root of sixteen is 4. Hence, this is the length of the side you wish to determine length of. Draw a little picture with the 3 - 4 - 5 on it; then change the numbers to the lengths you know, and you should easily see how to determine the answer.
Good luck.... hope I helped.
geo

[Rapier]

Call a surveyor. They are fairly well versed in angles.

[Daver7]

Georgerkahn gave the best answer. M-techs is okay if you always have internet access.

[44MAG#1]

Square the hypotenuse, square the known side. Subtract the difference. Take square root of the difference

What is it is the hypotenuse one doesn't know?

[fc60]

Greetings,

What do you know about the triangle?

Length of any of the sides?

Angle created opposite the 90 degree angle?

Cheers,

Dave

[44MAG#1]

Greetings,

Hi

What do you know about the triangle?

That is has three sides.

Length of any of the sides?

I said the length of the unknown side so the others would be known.

Angle created opposite the 90 degree angle?

Dont know. Wouldn't that be established by the length of the known sides on a right triangle?

Cheers,

[kerplode]

If you know two sides of a right triangle, you can use the Pythagorean Theorem to find the other (as many have already stated)
314015

If you know a side and one of the angles, you can use trigonometry to find the other unknowns. Just remember that the sum of all the angles is 180 degrees...
314016

[Castaway]

The question was how to find an unknown side of a right triangle. No trig is needed. The hypotenuse is the side away from the right angle

[scattershot]

The square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides. Just find the square root for the measurement. Or,just use a ruler.

[Dave W.]

If you know two sides of a right triangle, you can use the Pythagorean Theorem to find the other (as many have already stated)
314015

If you know a side and one of the angles, you can use trigonometry to find the other unknowns. Just remember that the sum of all the angles is 180 degrees...
314016

40 years ago I used this stuff multiple times a day, now it all looks like Greek to me. If you do not use it, you loose it.

[JonB_in_Glencoe]

If there is an unknown side, then you just have two line segments.

[44MAG#1]

If there is an unknown side, then you just have two line segments.

What?
There are 3 sides to a Right Triangle

[JonB_in_Glencoe]

Being one side is unknown and we don't know if the hypotenuse is known or unknown, then it's a paradox much like Schrodinger's cat thought experiment. So I just stated what is known, that you have two line segments.

[44MAG#1]

Being one side is unknown and we don't know if the hypotenuse is known or unknown, then it's a paradox much like Schrodinger's cat thought experiment. So I just stated what is known, that you have two line segments.
The unknown means unknown length.
The other TWO sides are KNOWN.

[M-Tecs]

As a machinist/toolmaker I've been using two sides or one angle and one side to trig. hole location for right triangles since 1978.

https://owlcation.com/stem/Math-How-to-Calculate-the-Angles-in-a-Right-Triangle#:~:text=We%20can%20calculate%20the%20angl e%20between%20two%20sides,is%20enough%20to%20deter mine%20everything%20in%20the%20triangle.

We can calculate the angle between two sides of a right triangle using the length of the sides and the sine, cosine or tangent. To do this, we need the inverse functions arcsine, arccosine and arctangent. If you only know the length of two sides, or one angle and one side, this is enough to determine everything in the triangle.

[JonB_in_Glencoe]

is the hypotenuse is known?

[44MAG#1]

is the hypotenuse is known?
It is unknown. But it could be known so it would leave one of the other sides unknown.
Regardless how does one find the length of the unknown side?

[JonB_in_Glencoe]

Use the Pythagorean Theorem.

But you pose the question as a paradox, where the hypotenuse is unknown, or could be known. You need to know. Since we don't know, it's like Schrödinger's cat.

[44MAG#1]

Use the Pythagorean Theorem.

But you pose the question as a paradox, where the hypotenuse is unknown, or could be known. You need to know. Since we don't know, it's like Schrödinger's cat.

Let me simplify this for the posters.
One has a Right Triangle, the length of two sides are know. But one is not known. How does one figure the length of the unknown side.
That is as simple as my feeble mind can make it.
It could be one one of the sides that are on right angles to each other or it could be the hypotenus.
Thank you for your effort to get me to understand my Schroeder's cat.

[M-Tecs]

It is unknown. But it could be known so it would leave one of the other sides unknown.
Regardless how does one find the length of the unknown side?

If you don't want to do the trig use a online calculator like this. https://www.omnicalculator.com/math/right-triangle-side-angle

[JonB_in_Glencoe]

use the Pythagorean Theorem.
Do you not know Algebra?

[44MAG#1]

use the Pythagorean Theorem.
Do you not know Algebra?

I know the very basics of general math.

[kerplode]

Let me simplify this for the posters.
One has a Right Triangle, the length of two sides are know. But one is not known. How does one figure the length of the unknown side.
That is as simple as my feeble mind can make it.


You've already been given the procedure a multitude of times.

This is as simple as one can make it and still have it be a general solution:
314035

If you still can't grok it, visit the link M-Tecs posted and plug in your numbers...

[kerplode]

Here's a rando example...

Let's say you know a and c and want to find b
a = 10
c = 43

b = sqrt(c^2 - a^2) =>
b = sqrt(1849 - 100)
b = sqrt(1749)
b = 41.8210

[M-Tecs]

use the Pythagorean Theorem.
Do you not know Algebra?

Algebra works when you know two lengths of the right triangle. When you have only one length and one angle you need to use trig. Trig works for all right triangle questions. Algebra not so much. Do you not know trig?

https://jdmeducational.com/what-is-the-pythagorean-theorem-5-key-things-you-should-know/#:~:text=To%20find%20the%20leg%2C%20we%20solve%20t he%20Pythagorean,a%20multiple%20of%20the%20triple% 20%7B3%2C%204%2C%205%7D.

[44MAG#1]

You've already been given the procedure a multitude of times.

This is as simple as one can make it and still have it be a general solution:
314035

If you still can't grok it, visit the link M-Tecs posted and plug in your numbers...

I know I have been given it multiple times. I have read every post.

[JonB_in_Glencoe]

There were several posts earlier in this thread, some with pictures, that explain the Pythagorean Theorem, but you need to know Algebra to use the Pythagorean Theorem. The Pythagorean Theorem is what you need to find the unknown length. Without that understanding, you will be unable to find the unknown length.

I am sorry for my clever attempts at humor (Schrödinger's cat) when I assumed your question was a red herring.

[JonB_in_Glencoe]

Algebra works when you know two lengths of the right triangle. When you have only one length and one angle you need to use trig. Trig works for all right triangle questions. Algebra not so much. Do you not know trig?

https://jdmeducational.com/what-is-the-pythagorean-theorem-5-key-things-you-should-know/#:~:text=To%20find%20the%20leg%2C%20we%20solve%20t he%20Pythagorean,a%20multiple%20of%20the%20triple% 20%7B3%2C%204%2C%205%7D.

We were told we have two lengths. So there's that.
.
Sadly, I am weak in Trig. I did use trig in School 40 years ago, but I haven't needed to use it since. I do use Algebra all the time ;)

[kerplode]

And another...

You know a and b and want to find c
a = 23.275
b = 197.443

c = sqrt(a^2 + b^2)
c = sqrt(541.725625 + 38983.738249)
c = sqrt(39525.463874)
c = 198.8101

[kerplode]

I know I have been given it multiple times. I have read every post.

OK, fair enough. What about it do you not understand?

Look at the examples I posted and see if that makes it clearer...

[kerplode]

Here's the classic right triangle...

b = 4
c = 5

a = sqrt(5^2 - 4^2)
a = sqrt(25 - 16)
a = sqrt(9)
a = 3

3, 4, 5...

[kerplode]

using trig to find a of the above:

a = b/(tan(arcsin(b/c))
a = 4/(tan(arcsin(4/5))
a = 4/(tan(53.1301)
a = 4/1.333
a = 3

[rockshooter]

"Call a surveyor. They are fairly well versed in angles."

or a politician.
Loren

[varmintpopper]

You Brainies give Me a Head ache

[William Yanda]

What is it is the hypotenuse one doesn't know?

The hypotenuse is the side opposite the 90 degree angle, or the longest side.

[44MAG#1]

The hypotenuse is the side opposite the 90 degree angle, or the longest side.

I know what the hypotenus side is. I was talking about the length of it if it is unknown while knowing the lengths of the 2 other sides.
Again I know which side the hypotenus is.

[alfadan]

https://m.youtube.com/watch?v=hRKOenxiRaY&pp=ygUUaG9tZXIgZmluZHMgZ2xhc3NlcyA%3D
Reminds me of Homer finding some glasses.

Just the first 25 seconds or so.

[waksupi]

Algebra is an instrument of the devil.

From back in my carpet laying days, I remember if you measure 6' on an edge, and 8' on another edge, if you measure from point to point, you should have exactly 10'.

[TurnipEaterDown]

Algebra is an instrument of the devil.

From back in my carpet laying days, I remember if you measure 6' on an edge, and 8' on another edge, if you measure from point to point, you should have exactly 10'.

The method described is an application of Geometry.
3-4-5 is a common right triangle proportion. Can be linearly scaled to any appropriate dimension set. Larger (6-8-10, 9-12-15) simply improves precision of the setting of the right angle by reducing relative measurement error (you still measure as fine on tape measure -- 1/8th inch, or whatever you have chosen).

I taught this to a former friend who worked construction w/ me when he dropped out of high school and decried not needing "math". I told him he used it every day.
Killed himself a few years back. Shame.

[kerplode]

I know what the hypotenus side is. I was talking about the length of it if it is unknown while knowing the lengths of the 2 other sides.
Again I know which side the hypotenus is.

Lord Jesus...

At this point, I think you're just screwing with us, so I'm out.

Good luck with your missing sides.

[poppy42]

I know what the hypotenus side is. I was talking about the length of it if it is unknown while knowing the lengths of the 2 other sides.
Again I know which side the hypotenus is.

OK I think I possibly might know what is going on with you and I perfectly understand if not and you’re messing with me oh well I’m going to answer your question anyway. As everyone is stated the formula for figuring out the legs on a right triangle is a squared plus B squared equals C squared. You already know what c is. So if a+b =c than c-a=b or c-b=a. In other words if the hypotenuse is 25 and one of the other legs is 16 . Subtract 16 from 25 and you get 9. Figure out your square roots. The square root of 25 being 5 . The square root of 16 being 4. The square root of nine being 3. You now know the links of your 3,4,5 triangle. Oh almost forgot C always represents the hypotenuse! Does that help?
Showing someone the mathematical formula if they do not understand the symbols does them absolutely no good!

[MaryB]

Been way to many years since I used trig... algebra is easy still... calculus? Nope, forgot it!

[Texas by God]

The ONLY way that I got through THOSE classes in high school was to sit between Melanie and Penny and trade English help for Math help!


Sent from my iPhone using Tapatalk

[Beerd]

314047
..

[Chena]

This is the only truly depressing thread I have ever encountered on a cast boolits forum.

[elmacgyver0]

What?
There are 3 sides to a Right Triangle

Only one side to a left triangle.

[M-Tecs]

Lord Jesus...

At this point, I think you're just screwing with us, so I'm out.

Good luck with your missing sides.

same............

[Castaway]

This thread has become unbelievable! No wonder some folks have posts numbering in the thousands. The OP’s question has been answered multiple times in some variation of the same thing; yet, the compulsion to rephrase the obvious is almost funny. Something as simple as the question which has such a simple solution makes me question any advice given on something as potentially dangerous such as reloading advice

[alfadan]

So... how do I figure the weight of the mass of a triangle when I don't know any of the sides?
[smilie=1:

[Chena]

Deadpan answer for Alf: In physical terms, weight is not mass. Alternative sarcasm: abstractions are without weight, unless you consider the mass of the brain cells used in formulating smart-ass questions. Speculation: Famous Pig must be a trial lawyer.

[.429&H110]

This thread is fun,
shows the power of asking questions
and getting answers.
Best answer is "measure it".

Because in this world we do our best but
never find an exact 90 degree angle,
a straight line, round circle, or a perfect wife.
All depends what you measure with.

We get by in a messy crooked world
trying for three place accuracy
hoping for perfection in the next.

[nvbirdman]

Now if you know all three sides of a right triangle, how do you calculate the inside?

[JimB..]

OP must be trying to make a point, but I haven’t a clue what it might be.

[JimB..]

OP must be trying to make a point, but I haven’t a clue what it might be.

[PopcornSutton]

The wise old Indian has the trick....SOHCAHTOA
S=O/H
C=A/H
T=O/A

A cheap scientific calculator will get you there.

[44MAG#1]

Now if you know all three sides of a right triangle, how do you calculate the inside?

Base times height divided by two.