r = 2
The volume of a cone can be found using the following equation
[tex]V = r^2\frac{h}{3} \pi[/tex]
After putting in the information that we already know we get
[tex]16\pi = r^2\frac{12}{3} \pi \\16\pi = r^2(4) \pi \\4 = r^2\\ r = 2\\[/tex]
For proof's sake, we can try the equation again with the information we know
[tex]V = r^2\frac{h}{3} \pi \\V = 2^2\frac{12}{3} \pi \\V =4(4) \pi \\V = 16\pi[/tex]