Notes: Sometimes the string can introduce some errors because of its flexibility. Therefore, it's always a good idea to recheck the 3-4-5 after your lines are snapped. In addition to multiplying the ratio, you can also divide the numbers to get even smaller numbers.
How come the 2nd time your starting point is the same point but the first time your starting point is the outer edge on each side that is different length (4 and 3)? Doesn't that introduce an error in the diagonal?
Thank you for taking the time to comment! If you want to support my work, please drop some more comments on my other videos! This helps to wake up the YT algorithms. :)
Hi, thank you for the video very informative and right to the point. Question: I’m new to woodworking and I was wondering what is the best way to make plywood residuals square, always worry about the factory edge and when I loose track of it I don’t know what to do. Thanks you!
Mathematician here. Nice mathematical video :-) It's actually not the Pythagorean Theorem that is used in the 3-4-5 method. (I don't think the video claims this, but some comments do.) Instead, it is the converse of the Pythagorean Theorem, which says: IF the sides (a, b, c) of a triangle satisfy the equation a^2+b^2=c^2, THEN the angle opposite side c is a right angle. In the 3-4-5 method, this is used for a=3, b=4, c=5. For the same reason, there is also a 5-12-13 method. (And infinitely many other similar methods that are not just scaled versions of these to methods.) Another funny thing I have noticed: Almost all woodworkers on RUclips say "square" when they mean right angle (when two lines are perpendicular/orthogonal) :-)
@@noobjitsu1743 thanks bro, I looked into it some more and managed to wrap it around my somewhat empty head lol, was never great with Math, but still, thanks for the reply
Guys just start out with a any number that is a multiple of 3. Then however many times 3 goes into that number, multiply 4 and 5 by that same number. At the end, the measurement between the 3 side and the 4 side should equal 5 times whatever the number was you used to multiply with. If you start with 3x4=12. Then multiply the 4 and 5 by 4 also. 16 and then you would get 20 between the first two. It's really really simple if you know the multiplication table.
Hey man! Chalk lines are used mostly in carpentry/construction and work great for laying out lines for house walls, flooring, roofing, and cutting plywood just to name a few. Great tool.
We use a chalk like to transfer a line to a concrete slab, sub floor or any other type of substrate in order to follow. We use this line to keep all the material straight and square, it is very important to follow. If you don’t follow your line correctly, you can have a huge mess on your hands and its a nightmare to fix if you don’t "catch it" right away.
I did a diagonal using a single taunt string off each corner of the 36' apart stakes...stake one at (0) stake 2 at (36) 36Ft x 40Ft=54'2.75" Diag. corner to corner if memory serves me ... maybe not but ultimately when my numbers met diagonally my sides were 36 left side @ (40ft) and 38ft 6" right side @(40 ft) three times kept coming out using a 54ft 2" (same string tied off)...which corner is out is the need to know using a single string 54ft 2.75" off stake 1 @ 0 and stake 2 @36Ft? How is the parallels off ???
very cool. it got me thinkning.. situations that are square but not 3-4-5 or a simple multiple like 6-8-10, Is it true that every square 3 sided measurement is a derivative or multiple of 3-4-5? Kind of like if a truw box is really square, divided by itself is 1. So every truly square triangle measurement would have to be equally proportionate to 3-4-5...? never thought this deep before lol
Very nice. I have a question what if I’m working on a frame 48x24 inches, using 3-4-5 what distance do I use? 3 4 and 5 inches are too small, and 3 4 and 5 feet is too large, so guide me please.
Fantastic question Gary! Just as you can multiply to make the ratio bigger, you can divide to make it smaller. So for your project one option would be to divide the 3'-4'-5' by 2 to get 1.5'-2'-2.5'. Cool right?!
If you prefer integers that are as large as possible (and still inches), then you can multiply by an integer n so that 3*n is at most 24, and 4*n is at most 48, i.e., you multiply by n=8: 3 becomes 3*8=24, 4 becomes 4*8=32, 5 becomes 5*8=40. Therefore, you now have a 24-32-40 method.
It’s a ratio. It doesn’t matter what the measurements are as long as they are 3-4-5. You could use 24 on the short side, 32 on the second side and 40 on the hypotenuse. 24-32-40 is the same as 3-4-5. Better still, forget it altogether and just measure the diagonals.
Cool math tricks - interestingly, while the 3-4-5 Triangle method clearly speaks to Pythagorean mathematics, the diagonal method also lends a concept from another famous mathematician - Ptolemy (as in, Ptolemy's theorem: en.wikipedia.org/wiki/Ptolemy's_theorem)
If you take four and divide by 3 you get 1.33. if you take five and divide by 4 you get 1.25. does this mean you can take the shortest side of what you need to measure the full length of it. Multiply that by 1.33 measure that out. Then you take whatever the four number was which is the result of the 1.3 multiplication multiply that by 1.25 and that's the length between those two measurements. I guess the only benefit was your first measurement you could make it whatever the full length was. But it wouldn't work on a square because the second number would be longer than what's available to measure. I guess where the square you just measure from corner to corner and get the same measurement but sometimes that's a little tedious. I was just trying to think outside the box lol.
Don't worry about unit of measure. It can be something you invent. What matters is the 3,4,5 all being multiplied by the same number each time. It's much easier to understand with the short simple explanation. The longer it takes to explain this the more confusing it will get.
You don't have to go 3',4',5'. Use multiples of 3 if that works better. Say you use 12. 3x4=12. Now multiply 4 x 4 up the other side. That's 16". Now if you measure between them you should get 20 because 5x4=20. I just used 12, which is 3x4. Then I multiplied the next two numbers also by 4. You can do it however works best for the project. Just start with any number that is a multiple of 3.
@@vmax4575 rectangles are NOT squares, a square implies both length(x) and width(x) are the same , hence x². In a rectangle length and width are different sizes. OK , an apple is not a pear, although they are both fruits
Notes: Sometimes the string can introduce some errors because of its flexibility. Therefore, it's always a good idea to recheck the 3-4-5 after your lines are snapped. In addition to multiplying the ratio, you can also divide the numbers to get even smaller numbers.
How come the 2nd time your starting point is the same point but the first time your starting point is the outer edge on each side that is different length (4 and 3)? Doesn't that introduce an error in the diagonal?
Use this all the time in laying out slabs and footings, wall placement, ensuring square openings. Countless uses for this method. Thank you Pythagorus
Representing the homeland, Tennessee! Good to see my Tennessee neighbors out here putting in work.
Your explanation is easy to follow n understand. Thank you.
Best explanation I've heard so far
I believe you are the best channel in America .
That is very kind of you to say Elton!
I can believe I learned that today. Thank you
I love to these videos they are fast and to the point. You can always pause or rewind if necessary.
I tried watching a few different videos, but your videos I understood! Thank you.
Thank you for watching!
So well explained sir. I thank you.
Great! Thank you for the perfect explanation. ❤
Thank you! Been looking for a straightforward explanation and you are it. Appreciate you taking the time. Helped me out-be well...
Thank you for taking the time to comment! If you want to support my work, please drop some more comments on my other videos! This helps to wake up the YT algorithms. :)
I can not imagine, that somebody dislikes this video! Many thanks, Josh, you keep it simple and understandable. I get it as an amateur.
I appreciate that Milan!
Hi, thank you for the video very informative and right to the point. Question: I’m new to woodworking and I was wondering what is the best way to make plywood residuals square, always worry about the factory edge and when I loose track of it I don’t know what to do. Thanks you!
Thank you, sir, with you today!
As a flooring contractor, this is a method I live by every time I do lay out
I used to set buildings out with that technique. But obviously in meters. 👍🏻
thanks very much for uploading
Mathematician here. Nice mathematical video :-) It's actually not the Pythagorean Theorem that is used in the 3-4-5 method. (I don't think the video claims this, but some comments do.) Instead, it is the converse of the Pythagorean Theorem, which says: IF the sides (a, b, c) of a triangle satisfy the equation a^2+b^2=c^2, THEN the angle opposite side c is a right angle.
In the 3-4-5 method, this is used for a=3, b=4, c=5.
For the same reason, there is also a 5-12-13 method. (And infinitely many other similar methods that are not just scaled versions of these to methods.)
Another funny thing I have noticed: Almost all woodworkers on RUclips say "square" when they mean right angle (when two lines are perpendicular/orthogonal) :-)
:)
heya, I'm a tad confused, I thought if 3-4-5 worked, 1-2-3 would also work, but it doesn't lol, can you explain more into why? thanks
@@rustyneedles3743Cause its 3 squared + 4 squared = 5 squared
@@noobjitsu1743 thanks bro, I looked into it some more and managed to wrap it around my somewhat empty head lol, was never great with Math, but still, thanks for the reply
@@rustyneedles3743 Np i got a test on it today so figured id help!
Awesome. Thanks. Just made a bench top and need to put straight and square dog holes.
Thanks! I've watched a couple of your video's, all are excellent. You are the first person that I felt I got enough out of it to donate
Awe, thank you so much Jack! I really appreciate your generosity.
I loved this tip! Thank you!
Glad it was helpful Shaun!
Show de bola! Greetings from Brazil!
Thank you! Cheers!
Very good information about square tank you
Excellent lesson!
Thank you for your video is very simple and will be help me so much
Glad it helped
Thanks Josh!
Thanks a lot! Didn't realize so easy a method.
I know right, and you can use it in so many different places.
Thanks I like how you show the numbers close up now I get it
Glad to help
Thanks for the video
Best explanation I’ve seen 👌👌understand it fully now ,cheers buddy
Great to hear!
Guys just start out with a any number that is a multiple of 3. Then however many times 3 goes into that number, multiply 4 and 5 by that same number. At the end, the measurement between the 3 side and the 4 side should equal 5 times whatever the number was you used to multiply with. If you start with 3x4=12. Then multiply the 4 and 5 by 4 also. 16 and then you would get 20 between the first two.
It's really really simple if you know the multiplication table.
Thank You Very Much.
You are very welcome. :)
Love the tips
Very educative
Awesome! Thank you for the comment.
Thank you alot for a good lesson
awesome video
well done
great
What’s the chalk line cord all about? What’s its purpose and why did you “snap it” ... thanks Josh ✌🏼
Hey man! Chalk lines are used mostly in carpentry/construction and work great for laying out lines for house walls, flooring, roofing, and cutting plywood just to name a few. Great tool.
@@TrainingHandsAcademy ahhh I see! I saw one of my buddies use this the other day on a long slab but I was lost. Good to know! Thanks buddy
We use a chalk like to transfer a line to a concrete slab, sub floor or any other type of substrate in order to follow. We use this line to keep all the material straight and square, it is very important to follow. If you don’t follow your line correctly, you can have a huge mess on your hands and its a nightmare to fix if you don’t "catch it" right away.
Can you just divide the 5 by 2 to get a 45 degree projection?
Thank You
Thank you now I know the 345 method
Happy to help
The floor layout is snazzy
Thank you so much for sharing your knowledge bro
My pleasure
Genius!!
I did a diagonal using a single taunt string off each corner of the 36' apart stakes...stake one at (0) stake 2 at (36) 36Ft x 40Ft=54'2.75" Diag. corner to corner if memory serves me ... maybe not but ultimately when my numbers met diagonally my sides were 36 left side @ (40ft) and 38ft 6" right side @(40 ft) three times kept coming out using a 54ft 2" (same string tied off)...which corner is out is the need to know using a single string 54ft 2.75" off stake 1 @ 0 and stake 2 @36Ft? How is the parallels off ???
curious what if you were trying to build a 20 x30 building and your trying to make sure your floor joist are square?
Yes this work for that... just upscale the numbers like in the video's examples.
How would I use this if I need to set 4 power poles for a pole barn about 30x30 so it’s square
I would just use diagonal measurements for that. If the measurements are the same, you're building square. :)
Very useful
Shout Out From South Texas :) #New Sub :)
Welcome Robert!!
I also say, thanks 😊🤙👍👈
No problem 👍
very cool. it got me thinkning.. situations that are square but not 3-4-5 or a simple multiple like 6-8-10, Is it true that every square 3 sided measurement is a derivative or multiple of 3-4-5? Kind of like if a truw box is really square, divided by itself is 1. So every truly square triangle measurement would have to be equally proportionate to 3-4-5...? never thought this deep before lol
I would say yes, that is true.
I want to learn how lay a floor plan using a string of a building plan
Very nice. I have a question what if I’m working on a frame 48x24 inches, using 3-4-5 what distance do I use? 3 4 and 5 inches are too small, and 3 4 and 5 feet is too large, so guide me please.
Fantastic question Gary! Just as you can multiply to make the ratio bigger, you can divide to make it smaller. So for your project one option would be to divide the 3'-4'-5' by 2 to get 1.5'-2'-2.5'. Cool right?!
Metric!
If you prefer integers that are as large as possible (and still inches), then you can multiply by an integer n so that 3*n is at most 24, and 4*n is at most 48, i.e., you multiply by n=8:
3 becomes 3*8=24,
4 becomes 4*8=32,
5 becomes 5*8=40.
Therefore, you now have a 24-32-40 method.
It’s a ratio. It doesn’t matter what the measurements are as long as they are 3-4-5. You could use 24 on the short side, 32 on the second side and 40 on the hypotenuse. 24-32-40 is the same as 3-4-5. Better still, forget it altogether and just measure the diagonals.
Cool math tricks - interestingly, while the 3-4-5 Triangle method clearly speaks to Pythagorean mathematics, the diagonal method also lends a concept from another famous mathematician - Ptolemy
(as in, Ptolemy's theorem: en.wikipedia.org/wiki/Ptolemy's_theorem)
I need diagonal for 21/40 dimension metal building
This is like a math class.
So is run always 3 ft and rise at 4ft??? Or can we do vise vers??? Run being 4 and rise 3 ft?????
Yes, you can switch it up.
Subscribed
Thanks!
Flexible use of the Pythagorean Theorem
I’ve figured, thank you
How about big building lay out for square one.
Yes, this works for that too.
@@TrainingHandsAcademy Thank you ang can you make demo for that too?
God bless .
If you take four and divide by 3 you get 1.33. if you take five and divide by 4 you get 1.25. does this mean you can take the shortest side of what you need to measure the full length of it. Multiply that by 1.33 measure that out. Then you take whatever the four number was which is the result of the 1.3 multiplication multiply that by 1.25 and that's the length between those two measurements. I guess the only benefit was your first measurement you could make it whatever the full length was. But it wouldn't work on a square because the second number would be longer than what's available to measure. I guess where the square you just measure from corner to corner and get the same measurement but sometimes that's a little tedious. I was just trying to think outside the box lol.
does it work in metric???
Yes, any unit of measurement
Don't worry about unit of measure. It can be something you invent. What matters is the 3,4,5 all being multiplied by the same number each time. It's much easier to understand with the short simple explanation. The longer it takes to explain this the more confusing it will get.
@@TrainingHandsAcademy thank you for the great answer, makes sense
I see the concept here, but couldn't you just use the speed square to check the angle?
You can but the speed square is too small to get accurate readings on larger projects.
Adorable apprentice there, bud. Wish mine were that cute. 😂
ha, can someone explain to me, why 3-4-5 works, but 1-2-3 will not? they're literally the same thing? but it doesn't work ... I'm confused lol
(1×1)+(2×2) does not equal (3×3)
(3×3)+(4×4) does equal (5×5)
.25 speed is best for this
Bad ass
Yes, but will it work for a "LEFT" triangle! 👀😆😜😁🤣👍
😂
Unfortunately not.
Or I could say yes- it will work for communists!
@@Nitecrow314 You juz had to go there! 🤣
Am not getting 5'
Then you are out of square
You don't have to go 3',4',5'. Use multiples of 3 if that works better.
Say you use 12. 3x4=12. Now multiply 4 x 4 up the other side. That's 16". Now if you measure between them you should get 20 because 5x4=20. I just used 12, which is 3x4. Then I multiplied the next two numbers also by 4. You can do it however works best for the project. Just start with any number that is a multiple of 3.
respect for share your educate
Thanks for commenting!
Let's see if someone could actually do it.Not a carpenter .
Do what?
Your frame Is not a square,its a rectangle 😂😂
Actually aren’t rectangles squares. They just have unequal sized length but have ninety degree corners.
@@vmax4575 rectangles are NOT squares, a square implies both length(x) and width(x) are the same , hence x². In a rectangle length and width are different sizes. OK , an apple is not a pear, although they are both fruits
Got it coach!! 🫡
Very helpful thank you