Answer:
18
Explanation:
Alright so here you have to work backwards. the volume of a cylinder is pi*r^2*h.
Your equation: 486 pi = pi*r^2*6
You know the height is 6 feet, so you can get rid of the 6 feet hanging off of your equation by dividing both sides by 6:
81 pi = pi*r^2
Now you notice that both sides have pi. You can eliminate it by dividing both sides by pi:
81 = r^2
To isolate the r, radius, you have to take the square root of both sides, since a square root is the inverse operation of squaring. You get:
9 = r
Now that you have the radius, you can find the diameter by multiplying the radius by 2, because a diameter = 2 * the radius:
18 = d
Hope this helps!