How to square up.

Next we moved to the next corner. This had to be set at 90 degrees to the existing posts.
To achieve this we used some pythaguras theory. In a right angled triangle the length of the longest side is known as the hypotenuse. It's length squared will always be equal to the sum of the squares of the other two sides. H x H = (A x A)+(B x B). You need only to know any 2 lengths and the 3rd can be calculated exactly.
To get our right angle we measured the length of the original marking line and placed line out from this to a length of 5m.we then calculated the length of the hypotenuse. This was joined back to the other side to form a perfect right angle.
Sounds complicated but easy really. On such a big scale as this it is the only
The corner post was installed on this new line. We then created another triangle to give us our last corner and then simply joined the 2 new corners with a line.
The best way to check a rectangle for square is to measure It's diagonals. If equal it is square. The structure was found to be out only by 1cm. Not bad considering it was nearly 6m in length by 2m wide. I was very pleased.