Each side of a square has a length of 45. What is the perimeter of this square?

To find the perimeter of a square, you multiply the length of one side by 4, since all sides of a square are equal in length. Given that each side of the square is 45 units, the perimeter \( P \) is calculated as follows:<br /><br />\[ P = 4 \times \text{side length} \]<br />\[ P = 4 \times 45 \]<br />\[ P = 180 \]<br /><br />Therefore, the perimeter of the square is 180 units.