Answer:
166 mi
Step-by-step explanation:
The length of an arc of a circle is the product of the radius and central angle measure in radians. For this problem, the central angle is the difference in latitude. The degree measure is converted to radian measure by multiplying by π/180°.
distance = (42.9° -40.5°)(π/180°)(3960 mi) ≈ 166 mi
The distance between the two cities is about 166 miles.
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You can get an answer good within 0.1% by using 60 nautical miles per degree. The 2.4° difference in latitude gives 144 nautical miles, which translates to 166 statute miles, so gives the same answer.
