Chapter 4.1, Problem 81E

The latitude of any location on Earth is the angle formed by the two rays drawn from the center of Earth to the location and to the point of intersection of the meridian for the location with the equator. The ray through the location is the initial ray. Use 3960 miles as the radius of Earth.

Distance between cities. Amsterdam, Netherlands, is due north of Lyon, France. Find the distance between Amsterdam (latitude $52°\text{ 2 <msup> 3 <mo> ′ </mo> </msup> N}$ ) and Lyon (latitude $45°\text{ 4 <msup> 2 <mo> ′ </mo> </msup> N}$).