The volume of a rectangular prism is represented by the following equation:

where w is the width , l is the length, and h is the height
Replace
with
since the length is tripled


From this, we see that this new volume is 3x larger than the original. Thus, the volume is tripled when its length is tripled.
Let me know if you need any clarifications, thanks!
Having The Lack Of Information, We Can Only Give You An Equation.
So:
Quotient = Division.
R / 12 Is The Equation.
(If This Is Not What You Need, Put In More Info, And I Can Solve It. ;) <span />
√214= 14.6287388383278
Calculator maybe??