We are given the following radical
[tex]\sqrt[\square]{208}[/tex]Let us simplify the above radical.
We need to break the number 208 into the product of two factors
Notice that 16 and 13 are the two factors (16×13 = 208)
So, the radical becomes
[tex]\sqrt[]{208}=\sqrt[]{16\cdot13}=\sqrt[]{16}\cdot\sqrt[]{13}[/tex]Since 16 is a perfect square
[tex]\sqrt[]{16}\cdot\sqrt[]{13}=4\cdot\sqrt[]{13}[/tex]Therefore, the simplified radical is
[tex]4\sqrt[]{13}[/tex]