question: private float calculateAngleBetweenPoints ( float newRadius , float oldRadius , float distanceBetween ) { float cosRatio = ( ( distanceBetween * distanceBetween ) - newRadius * newRadius - oldRadius * oldRadius ) / ( - 2 * newRadius * oldRadius ) ; float radians = ( float ) Math . acos ( cosRatio ) ; return ( float ) Math . toDegrees ( radians ) ; }
target:  Calculates the angle between two points. Looks at the radius to the old and new points and then the distance between the two points.