For the distance between any pair of co-ordinates take the square root of the sum of the square of the difference in x co-ordinates and the square of the difference in y co-ordinates. A quick google search found this way to do the required in Google Sheets. Given a list of geographic coordinate pairs you can implement the Haversine formula directly in Excel.
A ruler is commonly used to find the the distance between two points.
So I used the formula I found at Latitude And Longitude In Excelunder the Great Circle Distances section by Chip Pearson. Here I have a spreadsheet which implements the well-known Haversine formula to calculate distance between 2 coordinates. So you could take the difference in X square it then add it to the difference of Y squared and then take the square root of everything. SQRT Cell1 - Cell22 Cell3 - Cell42.