The volume of a cone is [tex]V= \frac{1}{3} A_{\text{basis}}\cdot H[/tex]. Since [tex]A_{\text{basis}}=36\pi[/tex] and you know that basis is a circle you can conclude that [tex]\pi R^2=36\pi[/tex] and [tex]R=6[/tex].
If height [tex]H[/tex] equal to twice the radius [tex]R[/tex], then [tex]H=2R=2\cdot 6=12[/tex].
The volume will be:[tex]V= \frac{1}{3} \cdot 36\pi \12=144\pi[/tex] cubic units.
