Two identical squares are attached to each other by their sides so that a rectangle is obtained.

Two identical squares are attached to each other by their sides so that a rectangle is obtained. The perimeter of this rectangle is 42 centimeters. Find the perimeter of the square.

Take the x side of the square.
Then the length of the rectangle is 2x, the width is x.
The perimeter of the rectangle is calculated using the formula:
P = 2 (a + b), where a is the length of the rectangle, b is the width.
2 (2x + x) = 42.
2 * 3x = 42.
6x = 42.
x = 42/6 = 7 cm – side of the square.
P square = 4 * x = 4 * 7 = 28 cm.
Answer: 28 cm.