One side of the rectangle is 8 cm, and the adjacent side is 4 times larger. Find the perimeter of the rectangle.

To solve this problem, remember that the perimeter of a rectangle is the sum of the lengths of all its sides. Since in a rectangle the opposite sides are equal, then P = 2 * (a + b), where a is the length, b is the width. Knowing that the length is 4 times the width, we calculate what the length is equal to. The width is 8 cm.
8 * 4 = 32 cm.
Let’s calculate what the perimeter of the rectangle is.
P = 2 * (32 + 8) = 2 * 40 = 80 cm.
Answer: 80 cm.