You need to line the inside of a tank that is 6 ft. diameter and 40 ft. high. You are going to line only the sides with the lining. How many sq. ft. are needed?
if it is a tank with 4 sides then you would simply do 6 multiplied by 40 which equals 240 and then multiple 240 by 4 which equals 960.
6 * 40 = 240
240 8 4 = 960
960 squared feet
hope this helps :)