The height of the rectangular parallelepiped is 18cm. It is equal to the difference between the length

The height of the rectangular parallelepiped is 18cm. It is equal to the difference between the length and width of the parallelepiped, and the length is 4 times greater than the width. Find the area of the side faces of the parallelepiped.

Let the width of the parallelepiped be x cm, then its length is 4x cm. So 4x – x = 18.

Where, 3x = 18;

x = 18/3;

x = 6 (cm) – width.

4 * 6 = 24 (cm) – length.

The opposite faces of a rectangular parallelepiped are equal, that is, it is required to calculate the area of three rectangles, which is equal to the product of two adjacent sides.

Thus, the product of width and length is 6 * 24 = 144 (cm ^ 2);

width and height – 6 * 18 = 108 (cm ^ 2);

length and height – 24 * 18 = 432 (cm ^ 2).

Answer: 432; 108; 144.