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A circular area of 5 miles radius covers 50265.5 acres (to 1 dp) Area = pi*radius2, which with radius in miles will give you area as 78.53982 square miles, then multiply by 64 â¦ 0, since there are 640 acres in 1 square mile.
One acre equals 0.0015625 square miles, 4,840 square yards, 43,560 square feet or about 4,047 square metres (0.405 hectares) (see below).riginally, an acre was understood as a selion of land sized at forty perches (660 ft, or 1 furlong) long and four perches (66 ft) wide; this may have also been understood as an approximation of the amount of land a yoke of oxen could plough in one day.