The sum of the lengths of the three sides of a square is 12 m which is equal to the perimeter of this square.

To solve this problem, remember that a square is a quadrangle with 4 sides equal. The perimeter is the sum of the lengths of all its sides. P = 4 * a, where a is the side of the square. We calculate the length of the side of the square, knowing. that the sum of the three sides of the square is 12 meters.
12/3 = 4 meters.
Let’s calculate the perimeter of the square.
P = 4 * 4 = 16 meters.
Answer: 16 meters.