The width of the rectangle is 8.4 and the length is equal to the side of the square with a perimeter of 39.2 cm.

The width of the rectangle is 8.4 and the length is equal to the side of the square with a perimeter of 39.2 cm. Calculate the perimeter of this rectangle.

Since all sides of a square are equal, and the perimeter of a polygon is the sum of the lengths of all its sides, then the perimeter of a square can be found by the formula:
P = a + a + a + a = 4 * a.

Find the side length of a square whose perimeter is 39.2 cm.

4 * a = 39.2;

a = 39.2 / 4;

a = 9.8 cm.

The perimeter of the rectangle is found by the formula:
P = a + b + a + b = 2 * a + 2 * b = 2 * (a + b),

where a is the length of the rectangle, b is the width of the rectangle.

Find the perimeter of a rectangle with a length of 9.8 cm and a width of 8.4 cm:

P = 2 * (9.8 + 8.4) = 2 * 18.2 = 36.4 (cm).

Answer: P = 36.4 cm.