The answer is 134041.3m^3
The volume of a sphere with radius r is:
[tex]V=\frac{4}{3}\pi r^3[/tex]
an hesmisphere have half the volume of an sphere, then:
[tex]V_{hemisphere}=\frac{1}{2}\cdot\frac{4}{3}\pi r^3=\frac{2}{3}\pi r^3[/tex]
The hemisphere has a diameter of 80m then it's radius is 40m
then
[tex]V=\frac{2}{3}\pi(40m)^3=\frac{128000}{3}\pi\approx134041.3m^3[/tex]
