The volume of a cylinder is the area of the circular face times the length of the cylinder.
the area of a circular face is

hence the volume is

the Length "L" is 36 in
the diameter "d" is 3 in
Answer:
what I have to find ............???????
Answer:
r=6
Step-by-step explanation:
The area of a circle is given by πr². Note that this uses the radius, not the diameter.
Now, one quarter of this area (ABC) is given to be 9π.
So apparently:

If you solve this:
(divide both sides by π)
(multiply both sides by 4)
so
r = √36 = 6
so the radius is 6.