Pythagoras theorem

[Time's Ran Out]

3x3 + 4x4 = 5x5
9 +16 = 25

The sum of the squares forming a right angle of a triangle are equal to the square on the 3rd side .

Using this in tiling is a basic requirement to get a 90 degree angle.
If you take 2 points on a line 4 feet apart, draw an arc 3 feet long above and from the left point, draw an arc 5 feet long from the right point and where they cross is the point that forms the right angle between the 4 & 3 feet lines - a right angled triangle 345.
You'd need a very large folding square to be as accurate on large jobs.
The other geometry that should be understood is how to bisect a line. Once you have your lines straight you can move them parallel to suit your set out.

 

[Houston]

we would always check are setting out on floors to make sure they were square with 3-4-5 and you can always multiply 3-4-5 by 2 on bigger floors to give you that bigger square line.

 

[charlie1]

3x3 + 4x4 = 5x5
9 +16 = 25

The sum of the squares forming a right angle of a triangle are equal to the square on the 3rd side .

Using this in tiling is a basic requirement to get a 90 degree angle.
If you take 2 points on a line 4 feet apart, draw an arc 3 feet long above and from the left point, draw an arc 5 feet long from the right point and where they cross is the point that forms the right angle between the 4 & 3 feet lines - a right angled triangle 345.
You'd need a very large folding square to be as accurate on large jobs.
The other geometry that should be understood is how to bisect a line. Once you have your lines straight you can move them parallel to suit your set out.

Thanks for that, finally understand. (Arcs) so you could use string anchored at one of the points and a pencil?

 

[charlie1]

This guy I'm talking about fluffed about with a tape measure saying 3-4-5 but I could tell he had no method and was very in accurate.

 

[jamespaul]

on large floors I always get the site engineer or borrow his theodolite (dumpy )
you really need that accuracy or you,ll soon be in the ****

 

[Diamond Pool Finishers]

http://en.wikipedia.org/wiki/Pythagorean_theorem .

http://www.wikihow.com/Use-the-3-4-5-Rule-to-Build-Square-Corners

 

[radim]

I use it to find if walls are square for floor tiling. very accurate method.IMO

 

[charlie1]

I've never doubted it as the purest square you will find, just didn't know how to actually build it... Until now that is.

 

[The Legend; Phil Hobson RIP]

3x3 + 4x4 = 5x5
9 +16 = 25

The sum of the squares forming a right angle of a triangle are equal to the square on the 3rd side .

Using this in tiling is a basic requirement to get a 90 degree angle.
If you take 2 points on a line 4 feet apart, draw an arc 3 feet long above and from the left point, draw an arc 5 feet long from the right point and where they cross is the point that forms the right angle between the 4 & 3 feet lines - a right angled triangle 345.
You'd need a very large folding square to be as accurate on large jobs.
The other geometry that should be understood is how to bisect a line. Once you have your lines straight you can move them parallel to suit your set out.

John once more you put things better than I do.:lol:

 

[Dougs Third Go]

long corridors I'll use Pythagoras, but instead of 3,4,5 I'll use 5,12, 13,,same principle.