Hello!
In order to find the answer, we must go from feet to inches to centimeters.
There are exactly 12 inches in a foot, and we begin with 18 feet. In order to convert 18 feet to inches, we must multiply 12 by 18 (inches in a foot times the amount of feet we begin with):
12x18=216in
Now, we are down to 216 inches. There are 2.54 centimeters in an inch. We must now multiply 2.54 by 216 (amount of centimeters in an inch times the total amount of inches).
2.54x216=548.64
The answer to your question is 548.64cm.
I hope this helps you! Have a great day!