Volume of a cylinder formula = Pi x radius^2 x length (Pi are square)
radius = 1/2 of diameter, Pi = approx 3.14
35 inches across is the diameter so take 1/2 of that and square it (multiply it by itself) then multiply by Pi (3.14). Now you have the area of the circle in square inches.
Multiply that by the length (60 inches) to find volume in cubic inches.
1 gallon = 231 cubic inches. Divide 231 into last answer to convert cubic inches to gallons.
radius = 1/2 of diameter, Pi = approx 3.14
35 inches across is the diameter so take 1/2 of that and square it (multiply it by itself) then multiply by Pi (3.14). Now you have the area of the circle in square inches.
Multiply that by the length (60 inches) to find volume in cubic inches.
1 gallon = 231 cubic inches. Divide 231 into last answer to convert cubic inches to gallons.