Answer:
P = 4 sqrt(7)
Explanation:
The diagonal is sqrt(14)
The triangle is 45 - 45 -90
The side lengths would then be the hypotenuse divided by sqrt(2)
sqrt(14)/sqrt(2) = sqrt(7)
The perimeter of a square is
P =4 s where s is the side length
P = 4 sqrt(7)