3-4-5

[bluevin123]

Hi all,

please can someone explain the 345 method used on floors. I understand it can be mtrs or feet as long as there the same,and that 3ft one way 4ft another should make a measurement of 5 ft, but where do I start in a room for instance.
If someone could explain please in laymans terms,that would be great.
Thanks.
Vinnie.

[R Montgomery]

Not sure what you are looking for but I suppose it's just a method for determining whether two lines cross at or are at 90 degrees to each other ie square.If you measure and mark from the intersection of the lines,three along one line and four along the other the distance between the two marked points ( diagonally) will be exactly five if the two lines are square to each other.If it is not five then they are not square.
You can use this method to determine whether the room you are in is square or not.One way would be to draw two center lines in the room and to check these.Another would be to check the corners of the room.Ok enough of that.What are you actually trying to do?Also when checking square you might find it easier with a large framing square and some straight edges or long levels.

[brundlefly]

start where ever you want your 90% line dropped off a base line

3,4,5 can be anything

3 units, 4 units, 5 units
say 60cm (3x20)
80cm (4 x 20)
100cm (5 x 20)


this is a pdf i did a while ago about dropping a 90% line, see if that helps ...hope it doesnt complicate things more

Trammel & 3,4,5





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[lucius]

6-8-10 is more accurate if you have the room.
Lucius