What is the approximate distance between Portland, Oregon (45° north, 122° west), and San Francisco, California (37° north, 122° west). Use 3,960 miles for the radius of Earth.
From the given data in the problem, the longitude is essentially the same, and using the coordinates, the locations are 8° apart. The 8° is 8/360 of the circumference of the circle. The circumference is 2π • 3960. Substituting, (8 • 2π • 3960) / 360 = 4π • 44 = 553 miles. Thus, option B is the answer.
