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);
}

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 ) ; }
calculates the angle between two points . looks at the radius to the old and new points and then the distance between the two points .
