Formula of volume of a Sphere is : V = 4/3 πr³
Here, Diameter (2r) = 12, so radius (r) = 12/2 = 6 feet
Substitute it into the formula,
V = 4/3 π(6)³
V = 4/3 *216π
V = 288π Ft² [ Answer in the term of π ]
You can also solve it for numeral value by substituting the value of π = 22/7
V = 288 * 22/7 = 905.15 Ft² [ Answer in numbers ]
Hope this helps!