If the perimeter of a square is 8 cm, what is the length of the diagonal?

2 square root of 2

4 square root of 2

square root of 2/ 2

4 cm

1 answer

To find the length of the diagonal of a square when the perimeter is given, we can follow these steps:

  1. Find the side length of the square: The perimeter \(P\) of a square is given by the formula: \[ P = 4s \] where \(s\) is the side length of the square. Given that the perimeter is 8 cm, we can solve for \(s\): \[ 4s = 8 \implies s = \frac{8}{4} = 2 \text{ cm} \]

  2. Calculate the diagonal: The length of the diagonal \(d\) of a square can be found using the formula: \[ d = s\sqrt{2} \] Substituting the calculated side length: \[ d = 2\sqrt{2} \text{ cm} \]

Therefore, the length of the diagonal is \(2\sqrt{2}\) cm. The correct answer is 2 square root of 2.