# How to stake out a square/rectangle quickly



## Proulx06 (Jan 8, 2007)

I'm building backyard hockey rinks as a side job, and I've done it long enough to know what I'm doing. But one part of the process feels like it takes way too long, and that's staking out the four corners. It's step one when we show up to build the frame, and no matter how careful I am, I always end up being not square the first time I try. 

This is how I do it, using a 20x40 rink as an example:

-Pound one stake into the ground.

-Walk 40 feet (measured), pound another stake in. 

-Eyeball 90 degrees, then walk 20 feet. Pound another stake in.

-Eyeball 90 degrees, then walk 40 feet. Another stake.

-Hope that the last stake is 20 feet away from the first one. It never is. 

-Measure diagonals - they never match, often 2-3 feet off. 

This is when I get frustrated and while it hasn't happened yet, I don't want any of my customers to see me screwing around for a half hour on step one. Especially because the rest of the built is very easy.

What's the trick? I'm using a stick, string, and a 100ft tape measure.


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## joecaption (Nov 30, 2011)

http://larry-darter.suite101.com/guide-to-foundation-construction-a195122
Here's the way a real foundation is layed out.


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## Daniel Holzman (Mar 10, 2009)

The trick is to buy a transit or level capable of measuring a 90 degree angle. Since you do this commercially, a few hundred dollars for an instrument that can turn a right angle should not be overly burdensome. If this is too expensive, you can use the two tape approach. Use the Pythagorean theorem to determine the length of the diagonals. Set the first two pins, say 40 feet apart, then to set the third pin at the correct location, swing an arc at 20 feet from pin 2, and an arc at 44.72 feet from pin one. The intersection of the two arcs will be a right angle. Same approach for the last pin.


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## forresth (Feb 19, 2010)

how about a loop of rope with knots at 20', 40' and 44'8.5" for your 20x40?

you can also scale up the 3-4-5 thing as big as you want to make a big square out of 2x4s to better eyeball a 90degree angle. no reason you can't you a precision compass either to get accurate 90s


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## DexterII (Jul 14, 2010)

Scratched... slow typing again, but agree with Daniel and forresth.


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## user1007 (Sep 23, 2009)

How about a GPS application on your smartphone. Some handheld commercial GPS applications are accurate, from space, to within a centimeter or less. They are used to keep skyscrapers square and plumb as they rise 100s of stories in the air. Should work well for something like a skating rink. I had no need for one but saw a few in the android store. 

Set the first pin. Find out where you are. Set the other pins along the same or parallel or perpendicular compass projections. Use GPS to make sure you have not waivered.

As mentioned, if you do a lot of these, you might want to pick up some sort of transit. Civil engineering firms depreciate them and you can sometimes pick up nice ones for chimp change. There are models that project bright laser "chalk Lines" along right angles that construction folk use for foundations. Pawn shops may have them too although I am not sure I would trust a precision instrument from a pawn shop.

Whatever you do, you might want to position your longest parallel sides first rather than trying to "run the bases" around the corners and hoping to stay square as you work your way around.


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## joed (Mar 13, 2005)

I agree with Forresth. EIther use two tapes or preset length of rope to set the second pin using the diagonal. The third pin should just fall in place when you measure the 20 and 40 length.


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## jomama45 (Nov 13, 2008)

forresth said:


> how about a loop of rope with knots at 20', 40' and 44'8.5" for your 20x40?


That's actually an outstanding idea for a repetative lay-out like this scenario......... :thumbsup:


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## Ironlight (Apr 13, 2011)

forresth said:


> how about a loop of rope with knots at 20', 40' and 44'8.5" for your 20x40?
> 
> you can also scale up the 3-4-5 thing as big as you want to make a big square out of 2x4s to better eyeball a 90degree angle. no reason you can't you a precision compass either to get accurate 90s


This is what I would do. 

Put in first pin. Walk 40' and put in second pin. Walk perpendicular and when the 20' rope and the 44'8.5" in rope meet is exactly where your third pin goes. Flip the ropes to get your fourth pin.

For different sizes just find your diagonal with a^2 + b^2 = c^2


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## JoJo-Arch (Sep 15, 2011)

The 3:4:5 thing. 
In a triangle whose angle opposite the hypotenuse (the diagonal) is 90º, there are two operative theorems.


The sum of the squares of the two sides adjacent to the 90ºangle equals the square of the hypotenuse. (For sides of different lengths to 3:4:5)
The ratio of the sides to each other, must be in multiples of 3:4:5 
3&4 are the adjacent sides and 5 the hypotenuse. 3² + 4² = 5²

This means, for a triangle having sides in the following RATIOS, a right angle triangle is always formed.
 *In feet or metres*

Multiples of 1 Ratios 3:4:5 Formula 3² + 4² = 5²
Multiples of 2 Ratios 6:8:10 Formula 6² + 8² = 10²
Multiples of 3 Ratios 9:12:15 Formula 9² + 12² = 15²
Multiples of 4 Ratios 12:16:20 Formula 12² + 16² = 20²
*Multiples of 5 Ratios 15:20:25 Formula 15² + 20² = 25²*
Multiples of 6 Ratios 18:24:30 Formula 18² + 24² = 30²
Multiples of 7 Ratios 21:28:35 Formula 21² + 28² = 35²
Multiples of 8 Ratios 24:32:40 Formula 24² + 32² = 40²
And so on 
To apply the formulae, hammer a sharpened peg 2’’x2’’ in one corner then hammer a nail in the centre. This will be peg A
Using a 100’0’’ tape, hook on nail walk in a straight line (this will be the baseline and one edge of the square). Leave it on the ground.
Choose a multiple (say 5 in our case and the bigger, the more accurate it will be)
Walk along the tape, at the 20’0’’ mark, hammer another peg as in 1, above. This will be peg B. The line between A & B is the baseline.
Walk back to peg A, with a *second *tape, lay out the tape roughly by eye at 90º to the baseline, laying the tape on the ground.
Walk back to peg A. Unhook the first tape and hook the end on peg B.
Walk (with the first tape) diagonally towards the 15’0’’ mark on the second tape.
Cross the tapes. Pick up both tapes. With the tape from peg A (second tape) at 15’0’’ and the tape from peg B (first tape) at 25’0’’, stretch and hammer peg C with nail at the intersection of the tapes at the dimensions quoted. A, B & C now form a right angled triangle.
Put both tapes on peg A, measure out the two sides at right angles whatever your rink size is, and at the two points, hammer pegs D & E. (Tapes or line should just touch pegs B & C, from A)
Pegs A, D & E are now the three corners of your rink. To find the fourth corner, measure the diagonal between D & E, and using the second tape, hook on peg B and measure a side the same as the opposite side. Hook the diagonal tape back on peg A (mirror image the first tape) and where the tapes cross, hammer peg F. Pegs A, D, E & F form the rectangle of your rink. (for a 20’x40’ rink, the diagonal is 44.72’). Check both diagonals. If the same, you have a perfect rectangle.

The above is a bit long winded, but once you get the hang of it, you should map out the rink in less than 5 minutes. Cheers from Joe in Oz.


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## JoJo-Arch (Sep 15, 2011)

In my long winded explanation, I went into detail why it works and what you physically do. It's actually a lot easier than it sounds, all you need are 4 pegs and three tapes. Mark one tape 20'0'' mark, another at the 40'0'' mark and the third at 44'8.5". cross the tapes after putting pegs A and B 40'0'' apart to get the other two corners. Then get the other two corners by using the diagonals. Also my earlier explanation covers a rectangle of any size, not just 20x40, and can be used to set out a house or mark out a block.

Cheers, Joe from Oz


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