The perimeter of the square is 80cm. Calculate the area of the square.

To find the perimeter of a square, fold the 4 sides of the square.

P = a + a + a + a.

P = 4 * a.

Knowing the perimeter of the square, we find its side:

80 cm = 4 * a;

a = 20 cm.

The area of a square is found by the product of the sides of the square or by squaring the sides:

S = a ^ 2.

Find the area of the square:

S = a ^ 2 = (20 cm) ^ 2 = 400 cm2.

1 dm2 = 100 cm2.

400 cm2 = 400 cm2 / 100 cm2 = 4 dm2.

Answer: 4 dm2.