Answer:
$72
Explanation:
The display board is 9 foot by 9 foot.
To add a ribbon border around the board, we first calculate the perimeter of the board.
[tex]\begin{gathered} \text{Perimeter}=9+9+9+9 \\ =36\text{ foot} \end{gathered}[/tex]If ribbon costs $2.00 per foot, the cost will be:
[tex]\begin{gathered} \text{Cost}=36\times2 \\ =\$72 \end{gathered}[/tex]It will cost $72 to add a ribbon border around the entire display board.
