Answer:
36 feet
Explanation:
Let us first find the area of the of the flower bed. It is a rectangle, so:
A = 18 * 4.5 = 81 square feet
The square flower bed has the same area, therefore, the length of the sides of the flower bed can be gotten. The area of a square is:
![A = L^2](https://img.qammunity.org/2021/formulas/mathematics/high-school/hjv8dx0hkr74rjbngsbc44wzu9r2hf4514.png)
![81 = L^2\\\\L = √(81)](https://img.qammunity.org/2021/formulas/mathematics/high-school/jhdcw6cgwb37qudz5qgcmcqlrm1yhfv45u.png)
L = 9 feet
Next, we need to find the perimeter of the square flower bed:
P = 4L
=> P = 4 * 9 = 36 feet
He needed 36 feet of fence to enclose the entire square flower bed.