The square has all four sides equal therefore the perimeter is four times the length of any side of the square.
![P=4L](https://img.qammunity.org/2023/formulas/mathematics/college/dgtqokvznr3snajdy3g0ntkffmeevau8cb.png)
In this case, we have that all four sides are equal to 4.5. Then, L=4.5.
Using the perimeter formula:
![P=4(4.5meters)](https://img.qammunity.org/2023/formulas/mathematics/college/1x4zm0lpg3p6664xphlqjnri1juwemli4l.png)
![P=18\text{meters}](https://img.qammunity.org/2023/formulas/mathematics/college/p43wa1eomsa4pwb2gqekfdzvz2kfxu80xj.png)
Hence, the perimeter is equal to 18 meters. The correct answer is
option D.