And yes, this is basic high school geometry - but no need for anyone to feel bad. Some people just forgot, others fell behind in school and got convinced they “suck at math”, so never caught up, and some have genuine learning disabilities. We all have things we’re better at than others, and things that challenge us that other people find easy. Fortunately, we got RUclips and the like to help us all learn, teach, and share.
I was taught this by my Dad when I was a boy. I don't remember learning this in school, but I worked in grounds care a school district for 24 years and I also used it for laying out sports fields, setting soccer goals and other things that needed to be set up square. I'm also a Mason and we use the "Pythagorean Theorem", as it is known in our symbolism as well.
I learned this years ago and have been using it ever since. Another tool that helps is to measure corner to corner diagonally both measurements should be the same.
A squared plus B squared = C squared. 3 squared is 9. 4 squared is 16. 5 squared =25. 9+16=25. Also works with 6, 8, and 10 and so on. As said in another comment, it’s the Pythagorean Theorem.
It works with any number. 3,4,5 just satisfies the equation with whole numbers. But any numbers can be plugged into the equation with a little more involved math.
@@mopreppinmolivin Yeah, sure can. I worked in construction and as a carpenter. We used this to square up foundation lines and such, so there wasn’t an actual triangle involved, I guess other than the one we made when measuring from 3 to 4. And yeah as the foundation or whatever we were squaring got bigger, so did the A and B numbers. What’s kinda funny is when I first did it on the job at the direction of the boss, I don’t think about it being the theorem we had learned back in school. It happened a few years later when we had to figure out the length of 2x4 we needed to reach from the ground to a point on a wall at an angle to hang a tarp on as a weather shield to be able to work on the wall. One of the younger guys said , hey it’s a triangle, we can use that A squared, B squared theorem. I remember thinking I finally had a use for one of those things in real life. 😄
Ya, one of the first things I learned when I began framing , but you got it wrong,bud the diagonal is the 5' foot span,lol the 90* spans are 3' and 4' the diagonal to ensure it is square is a 5' length
I'm so old I went to engineering school before calculators were invented, so I used the 3-4-5 triangle a lot. Also during tests the professor normally proposed angles of 0, 30, 60, 90-degrees for calculations. It wasn't too hard to memorize the sine and cosine of those angles.
Agreed. In HS, we used boat speed*cos(ang) to determine the best angle of sail to the mark to minimize elapsed time. (not counting tactics, weather, etc.)
good and straight to the point. Very good- thanks for the video! I built a Tiny Home many Years ago and since it was on a trailer I had to level the whole thing any time I worked on it in the beginning which was a hassle, so I started just measuring stuff instead- I pretty much built the whole thing without a level and it turned out perfect! I didn't know this rule back then but I did/do know how to make something level/square without a level, but you gotta be precise; any slight imperfection building in such a way extrapolates and then you get all sorts of oddities if you get things wrong. The trick I used most- measure opposite corners, if they're both the same distance then it is square. *I remodeled/did Construction for almost 20 Years and one of my personal rules: measure x3 times, cut twice- I like to always cut a hair longer than I need, test-fit things, then trim what is needed off on the second cut- you can always cut more off but you can't add more back on!
Giving the actual formula on why this works would have been helpful. It’s called The Pythagorean Theorem. A²+B²=C² - ‘C’ is always the diagonal (hypotenuse) You can use any numbers you want for ‘A’ and ‘B’. 3-4-5 is nice because it works out to whole, easy to remember numbers, without any decimals or fractions. Example - If ‘A’=3 and ‘B’=4 then ‘C’ will = 5 -- 3²+4²=5² or 9+16=25 If ‘A’=10 and ‘B’=19 than ‘C’ will = 21.4709 -- 10²+19²=21.4709² or 100+361=461 (√ 461= 21.4709) Obviously not as clean looking but works and proves the theorem. Btw, √ is the sign for square root. Which is the opposite of ( ² ) squared. 10² =100 or √100 = 10 Everyone has a phone with a calculator that has a square root ( √ ) function on it, so no one should be afraid to tackle uneven numbers anymore. Your phone will do the hard work for you. You just need to know what to tell it to do 📱
@@snowgorilla9789 Correct! You can use your own hand as a unit measure if you want. 3 hands² + 4 hands² = 5 hands². (equations without whole units are a little more difficult, but will still work.)
If your working with close to 0 tolerances aim small miss small and always always always be perfectly level and plump . Always ! I’ve watched skilled workers get it square and plumb and not be level mistakes too often. Good video 👍
Also, when you use 2 different tape measures, that can mess you up. Not all tape measures are the same. Pull two tape measures out together and they can be an 1/8"-1/4" in difference over say 20-30 feet. I know, I have had my own tile & stone company for 40 years. Tape measures, even the same brand, are rarely the same when checked against each other, especially over a long distance.
This happened to me yeeeeears ago when I was building a barn. I'd measured with one tape near the structure. And since I didn't have power close to where I was at, I had to walk back to the saw and I had a different tape there. It took me a couple cuts to realize what was happening. I measured with the tape at the barn recorded the measurement, walked back to my saw used a different tape on the same measurement and then I would come back and I'd be a quarter 1/8 of an inch or so off and I was like what the heck is going on here!!!??? That's when I learned to only use one tape measure for all my measuring....
@@MadDestructionChaos Yep. Back in the day, we did huge, continuous mall, hospital, shopping center floors. I would lay out the tile for my guys and I learned the hard way to never use 2 un-checked tape measures when laying out a 10,000 square foot area of flooring. An 1/8" off in 20 feet will be 1" off in 160 feet and so on. I would have to buy 10-15, 100 foot tapes to find 2 that matched each other, even though they were all the same brand.
Never knew the "3-4-5 rule". I was taught something in elementary school called the Pythagorean Theorem that started that side A (squared) times by side B (squared) equals side C (squared). The "3-4-5 rule" (oversimplified) works so well because 3(squared is 9) plus 4(squared is 16) equals 5(squared is 25). It can actually work with lots of different numbers, not just multiples of "3-4-5". Now you should make a video about this, make yourself look really smart guy. 😁 Your welcome, have a good day
You can do this for any number, not just increments of 3,4,5. A squared (A x A) + B squared (B x B) = C squared (C x C). Add the A2 with the B2 and do the square root of that answer. That is the length of C. Also helps to have a Construction Calculator. Lots of Geometry formulas in there to speed things up a bit.
How do you know which line is out of square? You cn also pull diagonals since most square we work with are small enough. You should have the same diagonal measurement if your square.
Pythagorean Theorem : for any right triangle, the square root of the sum of squares of the two shorter sides equals the length of the third side. 3,4 and 5 are the shortest lengths that make for easy answers when calculating squares and square roots. Given the lengths of any two sides the length of the third side can be calculated by an algebraic rearrangement of the formula, A(squared) + B(squared) = C(squared)
I did flooring and our school is teaching apprentices to swing arcs to square a 90 degree line from the main lay line. Tape measures bend and we don’t have thirty foot long straight edges. It’s dumb and disastrous if you’re in a large room and staring out of the center. They also don’t understand what a high line is for either.
the sum of the squares on the legs of a right triangle is equal to the square on the hypotenuse (the side opposite the right angle). It's that simple. Learned it in elementary school. Not a trade secret if you were paying attention.
I use the rule, as i produce sports fields and line mark, having 100 long tapes helps heaps as it is easier to "square" the field, 30m x 40m x 50m , especially doing rugby league fields
If you are doing a large project, say tiling a huge area. You can take the 3 foot, 4 foot 5 foot measurements, and double it to infinity. That being, 6, 8, 10 feet. 12, 16, 20 feet. 24, 32, 40 feet, etc.
You can also multiply any distance in A times itself, then multiply any distance in B times itself, then add the 2 numbers together and square root the total to end up with the distance for C 😊 36x36=1296 48×48=2304 - 2304+1296=3600 - sq root(3600)=60 works with any distance. Sorry, my keyboard wont show me the Sq Root symbol for some reason.
Or use- (X squared plus T squared) squared root. Or (3x3 + 4x4)=25 square root is 5. Works for all numbers. Or buy a builder’s calculator and use run, rise and diagonal feature.
He kept it with the basics that everyone can understand. I look at it as speaking a different language or taking a different approach. Too many people get stuck in the weeds with math like this. Well, if you're using direct multiples like 30 and 40, it's the same 50. Keeps it easier on the less inclined.
There is also the 4’-6’-8’ rule pull a measurement at 4’ the 6’ Perpendicular from the same point and then take your tape from the end of each measurement and it should be 8’ if its not move line accordingly
The bigger the square the bigger the numbers should be. 3 4 5 is for something that’s like 10x10 6 8 10 would be your next bigger numbers…12 16 20 would be the next. Further the number is to the corners the more accurate you will be.
Yes, we use those numbers running two 300ft tapes out and a 10ft tape starting at 6 and ending on eight of the long tapes to create giant square/rectangular parking lots for festivals.
It will work with any numbers. If you take A and multiply it by itself 36x36= 1296, then take B and do the same 48x48=2304, then add the two together 3600 and sq root (3600) it will equal C- 60. But you can do this with any numbers. A could be 77.625 and B could be 91.875 and you could still use the same formula to come up with C.
The easiest way for me to see if something is square is to measure from opposite corner to opposite corner both ways if the match in measurement then it is square.
I guess I am fairly nieve in that down here in New Zealand I was taught this when I was in primary school and I assumed it was the same world wide. Obviously it wasn't Kiwi Rod
Jeeesh y'all... funny. ¹you dont need or want the 3-4-5 to put shingles on. ²You have to go with the roof line... square or not to start your rows. ³metal roofing-3-4-5 applies. Never w/asphalt shingles
Using a sextant on a ship , ... the sextant is one corner of a triangle , the sun is the 2nd, the ocean horizon is the 3rd ... Meaning the ocean is the base line of the triangle... Here's the question.... When was the last time you saw a triangle with a curved base line ?
You don't even need a Measure a piece of scrap wood will give you your units measure three times its length four times its length and five times its length or your foot Palm of your hand
I was always good in math in school, and have known this method forever. I used it to build a square patio around a tree, using bricks. I came to this video though - thinking there was some application for trading on the stock market ......... oops.
"But we won't ever use this geometry and algebra junk in REAL life!" said almost every 17 year old sitting in a math class. SMDH. People who DO things use algebra and geometry every time they DO something. Thanks for the short, sweet, boiled-down explanation of squaring up a site!
It's not a secret as a carpenter and a home builder I use it when I want to start a floor with tile or make sure a countertop's going to fit because the walls plus or negative out of square and it also works in different increments not just 345 but some increments it does not work in
I can't think of any more trolling of this "college grad" than the whooping he is already receiving!! Formal Education sure took a NOSEDIVE since the 60's-early 70's!!( that's roughly 55 years, Sir!)
This video has sparked some debate. Some think if you were not aware of this handy trick that you're an idiot. Some think the idiots that are labeling someone an idiot for not being aware of this handy trick makes them an idiot.
For those yard stakes, if you have some scrap wood or lumber around, you can cut three pieces to 3' 4' and 5' and lay them at the corner to give an initial square and a backup guide to keep the longer lines straight...📐
And yes, this is basic high school geometry - but no need for anyone to feel bad. Some people just forgot, others fell behind in school and got convinced they “suck at math”, so never caught up, and some have genuine learning disabilities.
We all have things we’re better at than others, and things that challenge us that other people find easy. Fortunately, we got RUclips and the like to help us all learn, teach, and share.
As a grounds keeper in a school district for 20 years, this was very handy in setting up all our sports fields.
I was taught this by my Dad when I was a boy. I don't remember learning this in school, but I worked in grounds care a school district for 24 years and I also used it for laying out sports fields, setting soccer goals and other things that needed to be set up square. I'm also a Mason and we use the "Pythagorean Theorem", as it is known in our symbolism as well.
I learned this years ago and have been using it ever since. Another tool that helps is to measure corner to corner diagonally both measurements should be the same.
A squared plus B squared = C squared. 3 squared is 9. 4 squared is 16. 5 squared =25. 9+16=25. Also works with 6, 8, and 10 and so on. As said in another comment, it’s the Pythagorean Theorem.
Yes, the Pythagorean theorem . I used it to square carpet. I also used six eight ten. Worked every time
It works with any number. 3,4,5 just satisfies the equation with whole numbers. But any numbers can be plugged into the equation with a little more involved math.
@@mopreppinmolivin Yeah, sure can. I worked in construction and as a carpenter. We used this to square up foundation lines and such, so there wasn’t an actual triangle involved, I guess other than the one we made when measuring from 3 to 4. And yeah as the foundation or whatever we were squaring got bigger, so did the A and B numbers. What’s kinda funny is when I first did it on the job at the direction of the boss, I don’t think about it being the theorem we had learned back in school. It happened a few years later when we had to figure out the length of 2x4 we needed to reach from the ground to a point on a wall at an angle to hang a tarp on as a weather shield to be able to work on the wall. One of the younger guys said , hey it’s a triangle, we can use that A squared, B squared theorem. I remember thinking I finally had a use for one of those things in real life. 😄
Any multiples of 3, 4, and 5 will work. Those are called “Pythagorean triples.”
It's not rocket science. But when Pythagoras theorize this equation way back when it was pretty damn close for that day and age.
Ya, one of the first things I learned when I began framing , but you got it wrong,bud the diagonal is the 5' foot span,lol the 90* spans are 3' and 4' the diagonal to ensure it is square is a 5' length
Yes ! Parallel lines and that works wonders
Came here to say that exact thing a2 + b2 = c2. Better known as the Pythagorean theorem.
Thanks for stating the correct mathematical formula.@@hunterdogztc
Laughs in Pythagoras
Hypotenuse = the square of the other sides
The thumbnail with the hypotenuse being 4 is very triggering.
That’s not the hypotenuse. The photo’s perspective is tricking you.
@@dirkniblickable You are correct.
@@AlexandruVoda lol often a faulty trigger is the most dangerous of all
@@dirkniblickableno. It’s not the perspective. It’s wrong
Indeed!
Everybody that needs to know it already does. It's one of the first things a flooring installer learns.
I'm so old I went to engineering school before calculators were invented, so I used the 3-4-5 triangle a lot. Also during tests the professor normally proposed angles of 0, 30, 60, 90-degrees for calculations. It wasn't too hard to memorize the sine and cosine of those angles.
Agreed. In HS, we used boat speed*cos(ang) to determine the best angle of sail to the mark to minimize elapsed time. (not counting tactics, weather, etc.)
Trade secret?!?! Pythagoras has entered the conversation…
:-))))
Pythagoreans theorem.
Nit just 345. 9810 etc
@@ArlatubeMaybe you mean 9,12,15.
Learned this in high school in the 60s. Used this as a shipfitter for 30 years. The longer the legs of the triangle the more accurate it becomes.
Pythagoras is laughing his ass off that the op doesn't know what a hypotenuse is.
good and straight to the point. Very good- thanks for the video! I built a Tiny Home many Years ago and since it was on a trailer I had to level the whole thing any time I worked on it in the beginning which was a hassle, so I started just measuring stuff instead- I pretty much built the whole thing without a level and it turned out perfect! I didn't know this rule back then but I did/do know how to make something level/square without a level, but you gotta be precise; any slight imperfection building in such a way extrapolates and then you get all sorts of oddities if you get things wrong. The trick I used most- measure opposite corners, if they're both the same distance then it is square.
*I remodeled/did Construction for almost 20 Years and one of my personal rules: measure x3 times, cut twice- I like to always cut a hair longer than I need, test-fit things, then trim what is needed off on the second cut- you can always cut more off but you can't add more back on!
I learned “ cut twice & it’s still too short “ at our lumber yard is really true. Thanks for the reminder !
Giving the actual formula on why this works would have been helpful. It’s called The Pythagorean Theorem.
A²+B²=C² - ‘C’ is always the diagonal (hypotenuse)
You can use any numbers you want for ‘A’ and ‘B’. 3-4-5 is nice because it works out to whole, easy to remember numbers, without any decimals or fractions.
Example - If ‘A’=3 and ‘B’=4 then ‘C’ will = 5 -- 3²+4²=5² or 9+16=25
If ‘A’=10 and ‘B’=19 than ‘C’ will = 21.4709 -- 10²+19²=21.4709² or 100+361=461 (√ 461= 21.4709)
Obviously not as clean looking but works and proves the theorem.
Btw, √ is the sign for square root. Which is the opposite of ( ² ) squared. 10² =100 or √100 = 10
Everyone has a phone with a calculator that has a square root ( √ ) function on it, so no one should be afraid to tackle uneven numbers anymore. Your phone will do the hard work for you. You just need to know what to tell it to do 📱
Or just use a stick and bit of string, three sticks, four sticks = five sticks
@@snowgorilla9789 Correct! You can use your own hand as a unit measure if you want. 3 hands² + 4 hands² = 5 hands².
(equations without whole units are a little more difficult, but will still work.)
If your working with close to 0 tolerances aim small miss small and always always always be perfectly level and plump . Always ! I’ve watched skilled workers get it square and plumb and not be level mistakes too often. Good video 👍
I was going to guff this, then I decided to actually pay attention.
This really is powerfully valuable!
You obviously never learned basic mathematics.
I don't know if you know but the 345 rule is become obsolete, it has been replaced I think 8 years ago by the 6810 Factor.
crap. i thought it was the 91215 rule.
Loving it. I'll bet some wouldn't know what you're talking about.
😅😅😅😅
😂😂
NO, it's 182430
I learned this in 1983 at age 17 as a new roofer laying out the roof with a chalk line to run 3 tab shingles straight up the roof.
Also, when you use 2 different tape measures, that can mess you up. Not all tape measures are the same. Pull two tape measures out together and they can be an 1/8"-1/4" in difference over say 20-30 feet. I know, I have had my own tile & stone company for 40 years. Tape measures, even the same brand, are rarely the same when checked against each other, especially over a long distance.
This happened to me yeeeeears ago when I was building a barn. I'd measured with one tape near the structure. And since I didn't have power close to where I was at, I had to walk back to the saw and I had a different tape there. It took me a couple cuts to realize what was happening. I measured with the tape at the barn recorded the measurement, walked back to my saw used a different tape on the same measurement and then I would come back and I'd be a quarter 1/8 of an inch or so off and I was like what the heck is going on here!!!??? That's when I learned to only use one tape measure for all my measuring....
@@MadDestructionChaos Yep. Back in the day, we did huge, continuous mall, hospital, shopping center floors. I would lay out the tile for my guys and I learned the hard way to never use 2 un-checked tape measures when laying out a 10,000 square foot area of flooring. An 1/8" off in 20 feet will be 1" off in 160 feet and so on. I would have to buy 10-15, 100 foot tapes to find 2 that matched each other, even though they were all the same brand.
Never knew the "3-4-5 rule".
I was taught something in elementary school called the Pythagorean Theorem that started that side A (squared) times by side B (squared) equals side C (squared).
The "3-4-5 rule" (oversimplified) works so well because 3(squared is 9) plus 4(squared is 16) equals 5(squared is 25).
It can actually work with lots of different numbers, not just multiples of "3-4-5".
Now you should make a video about this, make yourself look really smart guy. 😁
Your welcome, have a good day
You can do this for any number, not just increments of 3,4,5. A squared (A x A) + B squared (B x B) = C squared (C x C). Add the A2 with the B2 and do the square root of that answer. That is the length of C. Also helps to have a Construction Calculator. Lots of Geometry formulas in there to speed things up a bit.
3 smarties, 4 skittles, 5 m&ms?
How do you know which line is out of square? You cn also pull diagonals since most square we work with are small enough. You should have the same diagonal measurement if your square.
Pythagorean Theorem : for any right triangle, the square root of the sum of squares of the two shorter sides equals the length of the third side. 3,4 and 5 are the shortest lengths that make for easy answers when calculating squares and square roots. Given the lengths of any two sides the length of the third side can be calculated by an algebraic rearrangement of the formula, A(squared) + B(squared) = C(squared)
I did flooring and our school is teaching apprentices to swing arcs to square a 90 degree line from the main lay line. Tape measures bend and we don’t have thirty foot long straight edges. It’s dumb and disastrous if you’re in a large room and staring out of the center. They also don’t understand what a high line is for either.
the sum of the squares on the legs of a right triangle is equal to the square on the hypotenuse (the side opposite the right angle). It's that simple. Learned it in elementary school. Not a trade secret if you were paying attention.
13-12-5 is best for imperial. Use radius lines. Used to layout foundations w/30-40 corners by myself in @30 minutes.
I use the rule, as i produce sports fields and line mark, having 100 long tapes helps heaps as it is easier to "square" the field, 30m x 40m x 50m , especially doing rugby league fields
If you are doing a large project, say tiling a huge area. You can take the 3 foot, 4 foot 5 foot measurements, and double it to infinity. That being, 6, 8, 10 feet. 12, 16, 20 feet. 24, 32, 40 feet, etc.
You can also multiply any distance in A times itself, then multiply any distance in B times itself, then add the 2 numbers together and square root the total to end up with the distance for C 😊
36x36=1296 48×48=2304 - 2304+1296=3600 - sq root(3600)=60 works with any distance. Sorry, my keyboard wont show me the Sq Root symbol for some reason.
Or use- (X squared plus T squared) squared root. Or (3x3 + 4x4)=25 square root is 5. Works for all numbers. Or buy a builder’s calculator and use run, rise and diagonal feature.
On the screen you have got the 3, 4,and 5 muddled up and no mention of Pythagoreans do you even know what you are on about?
He kept it with the basics that everyone can understand. I look at it as speaking a different language or taking a different approach. Too many people get stuck in the weeds with math like this. Well, if you're using direct multiples like 30 and 40, it's the same 50. Keeps it easier on the less inclined.
They fukked it up in the intro picture on purpose...🫡 it's why I was drawn in to watch the video. Pretty slikk man😎
The cover photo on this clip has the hypotenuse as 4 while the two legs of the right triangle are 3 x 5. !! Proofread?
There is also the 4’-6’-8’ rule pull a measurement at 4’ the 6’ Perpendicular from the same point and then take your tape from the end of each measurement and it should be 8’ if its not move line accordingly
6 8 10
You would need to scribe an arc at the 5 measurement and intersect an arc at the 4 measurement for this to work.
Multiples of 3 4 5 are more helpful. Like 6 8 10 or 36 48 60 for example. This allows for ez scaling for larger projects.
learn this in the first week as carpenter apprentice , I tend to use a laser cross line these days:) much faster!
It's embarrassing that your diagram had the 4 on the diagonal - obviously you never used this rule.
They got you to look...😂😂
You can multiply 3/4/5 by the same denominator, ie: 6/8/10, 9/12/15 etc.
I'm not terribly mathy, so I'll ask: would a 6 8 10 accomplish the same thing, since they're all multiples of the base?
Surely you have the 4 and the 5 wrong in the thumbnail .
They purposely fukjed that up to draw us in... 😅 pretty skikk bro... they got us. And a shitload more of us to get more views🫡🫣 funny. 😐
I've known this since I was a kid. Still use it today
I taught this to my friend who had just hired a surviver to layout 3 acres of vineyard. He did it himself and I get a case of wine each year.
I use this all the time when laying out a swimming pool we are getting ready to dig and form.
There's even an easy formula to tell you how long the long side should be. True story!
It seems odd that the picture in the lead up is incorrect. Hard to understand why that would be wrong.
try 6 8 10 for squaring floors for tile
The bigger the square the bigger the numbers should be. 3 4 5 is for something that’s like 10x10 6 8 10 would be your next bigger numbers…12 16 20 would be the next. Further the number is to the corners the more accurate you will be.
And don’t forget to use/ read the same side of the tape
You can use evenly marked string.
Alot of people don't know what a water level is either. That comes in very handy if used right
Thank God he made this video. I couldn’t find only but two or 300 of the same video.
does it work if you double up.. like 6,8,10？
Yes, basically that would be 3 twos, by 4 twos, equals 5 twos.
Yes, we use those numbers running two 300ft tapes out and a 10ft tape starting at 6 and ending on eight of the long tapes to create giant square/rectangular parking lots for festivals.
5, 12, 13 also works. And 5 times 3, 4, 5 is 15, 20, 25 which is easy to remember.
It will work with any numbers. If you take A and multiply it by itself 36x36= 1296, then take B and do the same 48x48=2304, then add the two together 3600 and sq root (3600) it will equal C- 60. But you can do this with any numbers. A could be 77.625 and B could be 91.875 and you could still use the same formula to come up with C.
IN YOUR OPENING PICTURE YOU HAVE THE 5 WHERE THE 4 SHOULD BE AND VICE VERSA
you can times it, it dosen't always have to 3,4,5. x2 6,8,10 x3 9,12,15 x4 12,16,20 .... pick the one closeest to the size your going for
I learned that in Woodshop in 1987. My tacticts dont involve any fancy words though.🤔🤣🤘
The basics of Pythagoras’ theorem. Why not use the 5,12,13 rule too?
The easiest way for me to see if something is square is to measure from opposite corner to opposite corner both ways if the match in measurement then it is square.
The four and five measurement on the introductory photo at the beginning are reversed.
That was done so that you would click bait the video and respond; got me too.
5 12 13 also works along with many others.
Good on ya! Hardly anyone knows that 5,12, 13 is also a 90 deg. angle
You can also double the numbers. 3,4,5. Or 6,8,10. Or 12,16,20. Etc.
Thats right, we go that route to make larger objects more accurate. 👍👍
Is the thumbnail wrong just to get us to click?
Its not wrong, its perspective
@@james_gatlinNO! It is wrong. Perspective my ass!
@@james_gatlinmake a 345 triangle on paper and try to change your perspective so it looks like the thumbnail. It’s not perspective…
@@rustysteed8414 glasses, ASAP....go!!!
It also works for millimeters, centimeters, meters, and kilometers. Just saying.
It also works with 12 evenly spaced knots or marks of any kind no measuring required
Wow. 45+ years as a carpenter and I'm just now hearing this?😂😂😅😅
Pythagorean Theorem…very effective in golf too! 😁
I guess I am fairly nieve in that down here in New Zealand I was taught this when I was in primary school and I assumed it was the same world wide.
Obviously it wasn't
Kiwi Rod
I woulda thought it's the 543 rule down undah🤔
I'll show myself out...
NO that's the Australian version LOL
Kiwi Rod
Welp, at least I didn't say it sounds like you have a British accent 😝
That's a bit like the 6, 8, 10 rule. Kiwi ken
Well, its different because we don't use the metric system here in the US. :) lol
Please help!!! Why is your diagram incorrect??? Your hypotenuses dimension is 4, why???
Also complete a circle..... anyway way shape or form
Thanks for sharing
Everyone already knows this! I use 6, 8, 10 for larger applications.
By dad used this relationship as a bricklayer. I picked it up as a young lad in the 1950's.
Jeeesh y'all... funny. ¹you dont need or want the 3-4-5 to put shingles on.
²You have to go with the roof line... square or not to start your rows.
³metal roofing-3-4-5 applies. Never w/asphalt shingles
For anyone who cares. A²+B²=C² so take your measurements on 2 sides A²+B². Then, take the sq root of that total to get your diaganol line.
Using a sextant on a ship , ... the sextant is one corner of a triangle , the sun is the 2nd, the ocean horizon is the 3rd ...
Meaning the ocean is the base line of the triangle...
Here's the question....
When was the last time you saw a triangle with a curved base line ?
My grandson asked me why I had so many tape measures, i proceeded to show him this trick, needless to say he was amazed. Lol
5:12:13 or with a calculator any lenths that suit your area ,or buy a theodolite.
6,8,10 is also a squaring tip.
your picture is wrong. Three and four at right angle, five reaches point to point at angle
You don't even need a Measure a piece of scrap wood will give you your units measure three times its length four times its length and five times its length or your foot Palm of your hand
The 345 can be 6810 or121620 depending on the size of the building it is not meant for triangles kapeesh
I was always good in math in school, and have known this method forever. I used it to build a square patio around a tree, using bricks.
I came to this video though - thinking there was some application for trading on the stock market ......... oops.
"But we won't ever use this geometry and algebra junk in REAL life!" said almost every 17 year old sitting in a math class. SMDH.
People who DO things use algebra and geometry every time they DO something. Thanks for the short, sweet, boiled-down explanation of squaring up a site!
Stay at the bottom of the pin or make sure your pin is plumb
It's not a secret as a carpenter and a home builder I use it when I want to start a floor with tile or make sure a countertop's going to fit because the walls plus or negative out of square and it also works in different increments not just 345 but some increments it does not work in
Double the formula for larger areas….. etc… etc
More accurate to pull the diagonal.
6-8-10 is what the old timers taught us back in the day
Trade secret? Ok here’s another ‘trade secret’.
Sandwiches are made with bread, filling then, wait for it, Another slice of bread. 🤪
Check the thumbnail mate. the Hypotenuse is five (5), not four (4). A bit shabby!!
of course the 3 4 is on the right angle side the 5 is across the ends of right angle
I think in terms of units. 3 units by 4 units for example.
So something everybody learned in math class and is one of the first things a labourer learns on the construction site is a "trade secret"?
It's called the Pythagoras theory, been using it for years, taught it at school.
It can also be 6 8 10 or 9 12 30 and so on.
Sounds like he paid attention in high school geometry class. 👍
I have an aluminum one fold up
I can't think of any more trolling of this "college grad" than the whooping he is already receiving!! Formal Education sure took a NOSEDIVE since the 60's-early 70's!!( that's roughly 55 years, Sir!)
If you're doing anything very big you better be able to figure a hypotenuse the corect way
This video has sparked some debate.
Some think if you were not aware of this handy trick that you're an idiot.
Some think the idiots that are labeling someone an idiot for not being aware of this handy trick makes them an idiot.
When you get numbers tangled . Remember , tangles , rightangles .
The very first triangle you showed with the side measurements was wrong
Finding a square wall for tiling a floor.
The first thing I learned in Grade 6 Geometry - 3 - 4 - 5.
Thats is how to get 90 degree right angle.
For those yard stakes, if you have some scrap wood or lumber around, you can cut three pieces to 3' 4' and 5' and lay them at the corner to give an initial square and a backup guide to keep the longer lines straight...📐
I used 3’x4’=5’ in the coal mine to set survey line for 90° turn for cross cut😢