Write the known parameters of the rectangular figure. In addition to the perimeterand to find the area needs to be known is another value either side of the rectangle.
According to the formula, the perimeter of the rectangle is, as the sum of all its sides. Because in a rectangle opposite sides are equal, we can write the formula for the perimeter: P = (d+c)*2, where d and c are the adjacent sides of shapes.
The area of rectangular shapes is determined by the product of its two adjacent sides: S = d*c. Thus, knowing one side, you can easily find the area of the shape.
Substitute in the formula for the perimeterand the known values: one of the sides and the perimeter. Express from the resulting equations the second unknown side and calculate it. Substitute the value obtained into the formula area. Calculate the value of the S - square shape.