First. Let’s find the radius. The diameter of the circle is 6in. Radius equals to half of the diameter. That means r=6/2=3in
Now if we find the area of circle, we have to multiply the quadratic of the radius by pi.
A=(3in)^2*3.14=9*3.14=28.26in^2
Now we can find the volume by multiply the area and the height.
V=28.26*8=226.08in^3
Now if we find the cube volume
V=a*b*h=15*9*9=1215in^3
V(toral)=226.08+1215=1441.08in^3
I hope this helped :)