How does the volume of a cone change if its radius and height are both tripled?

The volume of a cone is pi(r2h)/3 
If the radius and height are both tripled, plugging this into the equation gives us
pi(3h(3r)2)/3
=pi(3h9r2)/3
=27pi(r2h)/3
which is 27 times the initial volume.
Thus if the radius and height of a cone are tripled, the volume multiplies by 27. 

Hey mate where is the graph