How do I measure for square in an open field?

Question

I am building a pole barn and I need to be sure that the corners are square can anyone tell me the how this can be accomplished. The measurements are 16' x 20'.

Answer 1

Measure corner- to- corner in one direction, then, do it again in the opposite direction (other corners).
This is called 'tramming'.
If the measurements are the same, your frame is square. If you have different measurement readings, adjust the footings until both measurements read the same.
Easy!
Bobby

Answer 2

Measure 6 feet from a corner A to a corner B and mark the spot as F. Now measure 8 feet from corner A to Corner C and mark the point as G. Now measure FG and it should be exactly 10 feet if the corner A is square.

Repeat this process at each corner.

Answer 3

Mark off a 3x4x5 ft triangle in each corner. As long as all three legs are taught you have a 90 degree angle.