Thread: 3-4-5 method to check for square on longer distances

Yep. Same ratio. Following from Pythagoras..
3x3 + 4x4 = 5x5
9x9 + 12x12 = 15 x15

As dabbler says it's a ratio. Doesn't matter if you use miles, yards, metres or whatever.

Can also use 5, 12, 13 or any multiple of them

5x5 + 12x12 = 13x13
25 + 144 = 169

Dabbler is spot on. So long as the ratio is kept the same, Pythagoras gets the job done. So long as you multiply and/or divide all three numbers (3-4-5) by the same number, it works. So, if you had a diagonal that was about 1200 long, what should the sides of the triangle be to check for square?

1200/5*3= 720
1200/5*4= 960

So in this case your right angled 3-4-5 triangle is formed by sides of the lengths, 720, 960 and 1200. In this case each of the original numbers (3-4-5) are multiplied by 240.

I bet Pythagoras dined out on this for years. One thing to watch when doing longer distances is the diagonal long length measurement needs to be checked for tape sag before reading off.

Now I see why I should've paid attention to math.

Thanks.

Howard

If theres a curvature in space time when you perform this measurement the ratio won't hold true.

It requires 4 axis including a point in time for it to really be consistent because in curved / warped space time the shortest distance between two points may not be a straight line.

Attempting to produce a complete system of universal science based only on the triumvirate of "measured constants" e, c, and h, has proven to be insufficient and incomplete.

It turns out that a minimum of four constants are needed to define all the properties of time and space.

Originally Posted by Timless Timber

If theres a curvature in space time when you perform this measurement the ratio won't hold true.

It requires 4 axis including a point in time for it to really be consistent because in curved / warped space time the shortest distance between two points may not be a straight line.

Attempting to produce a complete system of universal science based only on the triumvirate of "measured constants" e, c, and h, has proven to be insufficient and incomplete.

It turns out that a minimum of four constants are needed to define all the properties of time and space.

It's only wood work not space exploration.

Originally Posted by rustynail

I bet Pythagoras dined out on this for years. One thing to watch when doing longer distances is the diagonal long length measurement needs to be checked for tape sag before reading off.

as well as the other two lengths.

Cheers,
Joe

Tape sag?

Lucky that's not a localized space time warp curvature!

And if your working in the heat and its not a metal tape your working with, i.e. one of those fabric plastic coated things, then watch out for time dilation (Stretch) in the tape.

And don't forget to take in the gravity factor too


Sent from my iPhone using Tapatalk 2

In the long distant past, have used one piece of string marked at 3:4:5 for setting up corners for formwork and fencing - works a treat, is fast and accurate.

Originally Posted by Simplicity

And don't forget to take in the gravity factor too

And if you're pacing it, don't change boots half-way.

Originally Posted by Bob38S

In the long distant past, have used one piece of string marked at 3:4:5 for setting up corners for formwork and fencing - works a treat, is fast and accurate.

we had one like that too .. with a small knot every foot

there are an unlimited number of prime pythagorean triads ... but as many have said it could be feet, inches or yards and still work

regards david