Answer
Using dimensional analysis gives:
$1 acre = 43,560 ft^{2}, 1 mile = 5280 ft, 1 mile^{2} = 27878400 ft^{2}$
$435 \times 43,560 ft^{2} = 18,948,600 ft^{2}$
$18,948,600 / 27878400 = 0.680 mile^{2}$
Work Step by Step
Using dimensional analysis gives:
$1 acre = 43,560 ft^{2}, 1 mile = 5280 ft, 1 mile^{2} = 27878400 ft^{2}$
$435 \times 43,560 ft^{2} = 18,948,600 ft^{2}$
$18,948,600 / 27878400 = 0.680 mile^{2}$
