The area of a semicircle is 0.7693 square miles. what is the semicircle's radius?

Substitute the given information into the formula for area of a semi-circle and solve for r.
  A = (1/2)πr²
  0.7693 mi² = (1/2)πr²
  (2×0.7693 mi²)/π = r²
  √((2×0.7693 mi²)/π) = r ≈ 0.6998 mi

The radius of the semicircle is approximately 0.700 miles

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