Hello!
The answer is:
Anna will need 27 posts.
Why?
To calculate how many post does she need to place at the corners and every 2 feet around, we need to calculate the perimeter of the garden plot.
So, we can calculate the perimeter of the garden plot (rectangle) using the following formula:
[tex]Perimeter=2height+2width[/tex]
We know that:
[tex]height=9ft\\width=18ft[/tex]
Then, calculating the perimeter of the garden plot, we have:
[tex]Perimeter=2height+2width[/tex]
[tex]Perimeter=2*9ft+2*18ft=18ft+36ft=54ft[/tex]
Now, calculating how many post she will need, we have:
[tex]No.Post=\frac{Perimeter}{DistanceBetweenPost}\\\\\frac{54feet}{2feet}=27posts[/tex]
Hence, we have that Anna will need 27 posts.
