3-4-5 Triangle Method For Finding Square

Today i'm answering a subscriber's question by  showing how to use the 3 4 5 triangle method   for finding square this method is generally used  when a square such as a framing square is just too   small to get an accurate measurement of squareness  for example this method can be used when framing   walls decks porches it can be used for laying out  flooring as well as large woodworking projects it   has many uses and it's fantastic for establishing  a 90 degree angle when you don't have one so what   exactly is the three four five method well it's  actually just a ratio between whole numbers and   the smallest ratio that creates a right triangle  happens to be three four and five this triple   number or ratio has a name and it's called  pythagorean triples what might be the coolest   thing about these triples is that it's just a  ratio and that means that as long as you keep the   ratio there's an infinite amount of possibilities  for example if i multiply each side by 2 i get 6 8   and 10 which is the same ratio and will produce  a right triangle or i could multiply each side   by 6 and get 18 24 and 30. the possibilities  are endless so why is it so helpful to be able   to change these numbers well it's because you  can scale these triples up for large projects   or you can scale them down for smaller projects  for example if i'm building a small project i   could use three four and five knowing that those  measurements will actually take up most of the   project's footprint or if i was building a large  project where three four and five would only cover   a small portion of the project i could use 18 24  and 30. what's also nice about these numbers is   you can make them any unit of measurement you want  for example 3 4 and 5 could be inches feet meters   or any unit of measurement that works for  you let's take a look now at two different   ways to use this method the first way to use  it is for squaring projects like for frames   built-ins cabinets really any woodworking  or carpentry related project for example   here today i have a large wooden frame that  needs check for square because of its size i'm   going to use three feet four feet and five feet  because it covers most of the size of the project   and again that's a good thing because that means  the accuracy will be greater the first measure   will be taken from this corner on the outer edge  over to the left three feet and let's make a mark   the next measurement will be taken from that same  corner now up the long side of the frame up to   four feet and we'll make another mark the last  measurement is taken between those two points   which if our frame is square that measurement  will be exactly five feet but in this case as   you can see it's short by about a quarter  inch or six millimeters therefore in order   to square this frame up the frame would have  to move at this end to the right until we've   reached our measurement of five feet and as  you can imagine if projects are large enough   you will need a partner to hold the other end of  the tape again this method can be used for large   projects as well like home construction floor  layout walls decks porches just to name a few   i do have to mention at this point that there  is another way to check this frame for square   and that's to use diagonals this is where you  measure from one set of corners diagonally and   then from the opposite set of corners diagonally  if these numbers match then you know the project   is square we've actually already done a video  detailing exactly how to do this and i'll leave   a link in the notes section below so you can watch  it after this one now that this frame is square as   a whole we can also be certain then that this  side here is coming off of this side squarely   meaning that this is an exact 90 degree angle and  no matter if we extend this line all the way out   this piece will remain 90 degrees to this line  regardless of what side we measure it from now   that we cover the first method let's talk about  the second method which is laying out 90 degree   lines to each other some of the most common places  for this to be used would be in floor layout like   tile all aspects of home construction from rough  to finish and of course some woodworking projects   to demonstrate this method we're going to be using  a chalk line so let's pretend that the line on the   bench represents the threshold of an opening say  into another room or space now in order to get a   square line that runs through that other room  we'll need to use the three four five method   and to do this is pretty simple because it's very  similar to the first method we start by making a   reference point on this line and then measure over  from that point three feet and make another mark   with that take the chalk line now and extend it  out which would be into that hypothetical room   or in our case up the bench from there measure  from the starting point up the string four feet   make sure that the string is pulled taut and make  a mark and i've always found it very helpful just   to use a sharpie now all i have to do is swing the  string either to the left or to the right until   your diagonal measurement reads five feet and  then snap your line with that now you know that   these two lines are 90 degrees to each other and  you can use that new line to help with whatever   layout you need for your next project well that's  it for today's video i hope it's been helpful of   course if you have any questions or need specific  help and like to share some photos and videos   reach out to me on instagram thank you so much  for watching i'll see you in the next video

Channel: Training Hands Academy

Views: 188,879

Keywords: 3-4-5 method, how to, 3 4 5 triangle, 3 4 5, 3-4-5 triangle rule, 3 4 5 triangle method, home improvement, 3 4 5 method, 3 4 5 method square deck, training hands academy, construction tips, how-to (website category), 3-4-5 method how to get a perfect right angle when building structures, 3-4-5 method large scale, 3-4-5 method flooring, 3-4-5 method for tiling, woodworking, carpentry, square, diy, construction, angle, 345, layout, squaring, right, right triangle, construction layout

Id: IyYHOhBCqFE

Length: 5min 48sec (348 seconds)

Published: Sun Mar 21 2021