To solve this problem you must apply the proccedure shown below:
1. You must use the formula for calculate the area of a rectangle:
[tex]Area=(Length)(Width)[/tex]
2. Now, you must solve for the width:
[tex]Length=12^{\frac{1}{2} }ft} =12.5ft \\ Area=103^{\frac{1}{8} } =103.125ft^{2}[/tex]
[tex]Width=\frac{103.125ft^{2} }{12.5ft} =8.25ft[/tex]
Therefore, the answer is: [tex]8.25ft[/tex]
