Calculate angle between two Latitude/Longitude points

Question

Is there a way to calculate angle between two Latitude/Longitude points?

What I am trying to achieve is to know where the user is heading. For example, user is head

Answer 1

In The Javascript, I create a function name angleFromCoordinate in which i pass two lat/lng. This function will return angel between that two lat/lng

function angleFromCoordinate(lat1,lon1,lat2,lon2) {
    var p1 = {
        x: lat1,
        y: lon1
    };

    var p2 = {
        x: lat2,
        y: lon2
    };
    // angle in radians
    var angleRadians = Math.atan2(p2.y - p1.y, p2.x - p1.x);
    // angle in degrees
    var angleDeg = Math.atan2(p2.y - p1.y, p2.x - p1.x) * 180 / Math.PI;
    console.log(angleDeg);
    return angleDeg;
}

Working Code Snippet

function angleFromCoordinate(lat1,lon1,lat2,lon2) {
    var p1 = {
        x: lat1,
        y: lon1
    };

    var p2 = {
        x: lat2,
        y: lon2
    };
    // angle in radians
    var angleRadians = Math.atan2(p2.y - p1.y, p2.x - p1.x);
    // angle in degrees
    var angleDeg = Math.atan2(p2.y - p1.y, p2.x - p1.x) * 180 / Math.PI;

    document.getElementById('rotation').innerHTML ="Rotation : "+ angleDeg;
    return angleDeg;
    
}
     angleFromCoordinate(37.330604,-122.028947,37.3322109,-122.0329665);

Rotation :