Find the area of a rectangle if its length is 2 times its width and the perimeter is 126 cm.

The perimeter of a rectangle is twice the sum of its adjacent sides. Let the width of the rectangle be x and its length equal to 2x, then its perimeter of the given rectangle:

2 * (x + 2x) = 126;

Here are similar terms:

2 * 3x = 126;

6x = 126;

The unknown factor is equal to the product divided by the known factor:

x = 126: 6;

x = 21 (cm) – the width of the rectangle;

2 * 21 = 42 (cm) – the length of the rectangle;

The area of a rectangle is equal to the product of its length and width:

S = 21 * 42 = 882 (cm2).

Answer: The area of the rectangle is 882 cm2.