Understanding and calculating distances between points using lat/lon

Discussion created by linyiyi on Oct 31, 2016
Latest reply on Nov 1, 2016 by tkowal

Hello, I do not have a geometric background, but I have a research project requires me to calculate distances between, say, a conflict site and the nearest major city (with population more than 1000000). I wonder are there any good sources can help me understand how to calculate this distance and how this is done by ArcGIS (explain the formula used to calculate the distance in a simple way). Besides, are there any good source for illustrating how grid and centroid points are generated (and the math) in ArcGIS?