#### Answer

The prison cell had 12.5 more square feet than the shark tank.

#### Work Step by Step

We know that the area of a rectangle is given by:
$Area=length*width$
$A=lw$
We find the areas of the shark cage and prison cell.
Prison cell: $Area=5*9=45~feet^2$
Shark cage: $Area=5*(6\frac{1}{2})=5*\frac{13}{2}=\frac{5*13}{2}=\frac{65}{2}=32.5~feet^2$
We subtract the two areas:
$45-32.5=12.5=12\frac{1}{2}~feet^2$
Thus the prison cell had 12.5 more square feet than the shark tank.