Plzzz someone help meeee!!!! :(

Answer:
5 feet
Step-by-step explanation:
The rose garden is trianglar and so the total of the two shorter sides need to equal more than the longest side. In this case 4+x=9. 6,7, and 8 all meet these requirments but 4+5 is 9, 9=9 which means 5 feet cannot be used