keeping corners square

[duck spy]

I'm building a pen for my ducks it will be 50'x150',but forgot the formula to keep my corners square,know for small corners 3'-4'=5,so would it still be good if I went 30'-40'=50'.
Post will be 4x4 3' deep and 10' on center.
help&thanks
Todd

 

[wedge40]

Yes any mulitpul of 3-4-5 will work. 9-12-15, 15-20-25

Wedge

 

[atgreene]

You can also do diagonals. I do them all the time for slabs and foundations. Measure from one corner to the opposite corner (diagonally).

To calculate diagonals, Diagonal = the square root of Length squared + Width squared.

So:
150 x 150 = 22500
50 x 50 = 2500

22500 + 2500 = 25000

Square root of 25000 = 158.11388


Here's a link with a calculator: Area, Perimeter and Diagonal of a Rectangle - Geometry Calculator