To express the cube root of 216 using rational exponents, we can write the cube root in terms of an exponent.
The cube root of a number is expressed as raising that number to the power of \( \frac{1}{3} \). Therefore, the cube root of 216 can be expressed as:
\[ \sqrt[3]{216} = 216^{\frac{1}{3}} \]
Thus, the equivalent expression with a rational exponent for the cube root of 216 is:
\[ 216^{\frac{1}{3}} \]