The length of the rectangle is 3 times its width, and the perimeter is 32 cm. Find the length and width of the rectangle.

Let’s take the width of the rectangle as x, then its length is 3 * x. The perimeter is the sum of the lengths of all sides of the polygon. For a rectangle, the perimeter is found by adding two sides in width and two sides in length. Let’s make the equation:
2 * x + 2 * 3 * x = 32;
2 * x + 6 * x = 32;
8 * x = 32;
x = 32/8 = 4 (cm).
The width of the rectangle is 4 centimeters, then its length:
3 * 4 = 12 (cm).
Answer: the length of the rectangle is 12 centimeters, the width is 4 centimeters.