The perimeter of a rectangle is given by the following formula:
[tex]P=2\cdot(L+W)[/tex]Where L is the length and W is the width.
This rectangle's length is twice is width, thus:
[tex]L=2W[/tex]By replacing L in the perimeter formula, we can solve for W as follows:
[tex]\begin{gathered} P=2\cdot(2W+W) \\ P=2\cdot(3W) \\ P=6W \\ 208ft=6W \\ W=\frac{208ft}{6} \\ W=34.67ft \\ \text{And the Length is then} \\ L=2W=2\cdot34.67ft \\ L=69.33ft \end{gathered}[/tex]The length of the rectangle is 69.33 ft and its width is 34.67ft