If OA = 8
Let each side of the square be x
If OA = 8, then AC = 8 x 2 = 16
Using pythagora's theorem
Hypotenus^2 = opposite^2 + adjacent^2
16^2 = x^2 + x^2
16^2 = 2x^2
256 = 2x^2
Divide both sides by 2
256/2 = 2x^2/2
x^2 = 128
Find the squareroot of 128
The perimeter of a square = 4S
where S is the sides of the square
Perimeter = 4 x 11.31
Perimeter = 45.25
Approximately 45
The answer is 45