Answer:
2736 square feet
Step-by-step explanation:210 minus 18(9 times 2 )equals 192 then 192 divided by 4 (4 because 4 side )equals 48 (48 is the width) to get the length 48 plus 9 equals 57 (57 is the length) to get the area multiply length times width so 57 times 48 equals 2736 square feet