yayoF

private double distance(double startLat, double startLon, double endLat, double endLon, char unit){
  double theta = startLon - endLon;
  double dist = Math.sin(deg2rad(startLat)) * Math.sin(deg2rad(endLat)) + Math.cos(deg2rad(startLat)) * Math.cos(deg2rad(endLat)) * Math.cos(deg2rad(theta));
  dist = Math.acos(dist);
  dist = rad2deg(dist);
  dist = dist * 60 * 1.1515;
  if (unit == 'K') {
    dist = dist * 1.609344;
  } else if (unit == 'N') {
    dist = dist * 0.8684;

yayoF

Download the telegram Desktop client here https://desktop.telegram.org/
Go to the client location in terminal and extract the package with < tar xf archive.tar.xz >
Now you have a folder called < Telegram >
Move this folder to /opt
Double-click the telegram binary in /opt/Telegram/Telegram.
Bonus: to add Telegram to de "applications" menu, right-click the icon of the runing app and choose "lock to launcher"

bon appetit

sources:

yayoF

https://openvpn.net/index.php/access-server/docs/admin-guides/182-how-to-connect-to-access-server-with-linux-clients.html