The answer is C
Explanation:
The formula for the volume of a cone is 1/3(pi)r^2*h
Since it’s is in pi units you can disregard the pi part and focus on 1/3r^2*h
And since the height is six and the volume is 36, you divide 36 by 6 to get 6.
Finally since the radius is squared in the formula and you need a value of six, answer c is the only option that works
Hope this helps!