Accepted Answer
When you put the pieces of the field together, you have a rectangle that's 53 yards wide and 120 yards long.When you draw the diagonal, it divides the field into two right triangles.Each one has legs with lengths of 120 yards and 53 yards. The diagonal of the field is the hypotenuse of both right triangles. (120)² + (53)² = (the hypotenuse)²14,400 + 2,809 = (the hypotenuse)² 17,209 = (the hypotenuse)²The diagonal (hypotenuse) = √17,209 = 131.183... yards (rounded)I guess that's the longest straight line it is possible to run on a football field while staying in bounds.