How to calculate the distance of 100-200 meters down the street from my location (GoogleMaps)?

Question

Android

Good afternoon.
I have marks on the map (10 pieces). How can I make an alert about approaching any of these marks, let's say for 100 meters (there are no problems with getting my coordinates)?
That is, roughly speaking, I'm driving along H street, at the end of the street there is a mark. How can I display a message about approaching her for 100 meters?

Answer 1

standard
, although if you really need it, then the math is simple there, I somehow implemented it in sql

Answer 2

If there are no problems with obtaining coordinates, then what is the problem? Can't you calculate the distance?