How to show a location with respect to my current location?

How to show a location with respect to my current location?

I have a lat and longitude of my friend's location also my current
location. I want to show the position of my friend with respect to my
location, just like a compass - in an iPhone app. I know the function
didUpdateHeading -
-(void)locationManager:(CLLocationManager *)manager
didUpdateHeading:(CLHeading *)newHeading
{
NSLog(@"New magnetic heading: %f", newHeading.magneticHeading);
NSLog(@"New true heading: %f", newHeading.trueHeading);
}
I am not getting an idea about how to do this, Please help me.