Spherical distance between two points on Earth
<p>I am trying to find distance between two points on Earth. But all I know is their latitude and longitude range(Both points lie in that range) and the x and y coordinates on the USA map. I am using data from this website
<a href="http://www.dis.uniroma1.it/challenge9/download.shtml" rel="nofollow">http://www.dis.uniroma1.it/challenge9/download.shtml</a></p>

<p>I looked at some formulas for calculating the spherical distance but they seem to use the latitude and longitude for each point. How can I get the latitude and longitude for each point from this data?</p>