a) The volume of a sphere can be calculated using this formula;
[tex]V=\frac{4}{3}\pi r^3[/tex]
Where "r" is the radius of the sphere.
In this case you can identify that the diameter of the sphere is:
[tex]d=12ft[/tex]
Since the radius is half the diameter:
[tex]r=\frac{12ft}{2}=6ft[/tex]
Now you can substitute the radius into the formula and then evaluate, in order to find the volume. This is (rounded to the nearest hundredth):
[tex]\begin{gathered} V=\frac{4}{3}\pi(6ft)^3 \\ \\ V\approx904.78ft^3 \end{gathered}[/tex]
b) The surface area of a sphere can be found using this formula:
[tex]SA=4\pi r^2[/tex]
Where "r" is the radius.
Knowing the radius, you can substitute it into the formula and then evaluate. This is (rounded to the nearest hundredth):
[tex]\begin{gathered} SA=4\pi(6ft)^2 \\ SA\approx452.39ft^2 \end{gathered}[/tex]
The answers are:
a)
[tex]V\approx904.78ft^3[/tex]
b)
[tex]SA\approx452.39ft^2[/tex]
