The length of the rectangle is 12 cm, the width is 1/4 of the length. What is the perimeter of the rectangle?

Let’s find the width of the given rectangle.
According to the condition of the problem, the width of this rectangle is 1/4 of the length of this rectangle, and the length of this rectangle is 12 cm, therefore, the width of the rectangle is:
(1/4) * 12 = 12/4 = 3 cm.
Find the perimeter p of this rectangle.
The perimeter of a rectangle is twice the sum of the length and width of the rectangle, therefore:
p = 2 * (12 + 3) = 2 * 15 = 30 cm.
Answer: the perimeter of the rectangle is 30 cm.