A square is a two-dimensional figure with four right angles and four equal sides, with each side parallel to the side opposite. The square's simple structure requires only the length of a sole side to calculate its other dimensions: the area; the perimeter, or the measured length around the object; and the diagonals, or the distance from one corner to an opposite one. If given the area of a square, you can deduce the length of a side and then its other dimensions.
Calculate the square root of the area to find one of its sides. For this example, 11 is the square root of 121.
Multiply the side's measurement by four to calculate the square's perimeter. For this example, multiplying 11 by 4 results in 44.
Multiply the side's measurement by √2, or the square root of 2, to calculate the diagonals of the square. For this example, multiplying √2 by 11 results in 11√2.