Answer
$0.6797 mi^{2}$
Work Step by Step
To convert from acres to square feet, we multiply the area by 43560 because we are told that $1 acre= 43560 ft^{2}$. $435 acres×\frac{43560 ft^{2} }{1 acre}=1.895\times10^{7} ft^{2}$. Now we must convert the value to ft by taking the square root so $ft = \sqrt {1.895\times10^{7} ft^{2}}= 4353.15 ft$. Then to convert to miles, we divide by 5280 because 1 mile = 5280 ft so $ 4353.15 ft \times\frac{1 mi}{5280 ft} = 0.8244602273 mi$. Lastly to convert to square miles, we simply raise the miles to the second power.
$0.8244602273 miles^{2} = 0.6797 mi^{2}$