The perimeter of the parallelogram is 128 cm. One side is 3 times longer than the other. find the lengths of the sides.

Let one first side of the parallelogram be x centimeters, then the second side of the parallelogram is 3 * x centimeters. We know that the opposite sides in a parallelogram are equal, and the parallelogram perimeter is 128 centimeters. Let’s make the equation:
2 * (x + 3 * x) = 128;
x + 3 * x = 128: 2;
x + 3 * x = 64;
x * (1 + 3) = 64;
x * 4 = 64;
x = 64: 4;
x = 16 centimeters – the first side of the parallelogram;
16 * 3 = 48 centimeters – the second side of the parallelogram.
Answer: 16 centimeters; 16 centimeters; 48 centimeters; 48 centimeters.