code: private static float angleDeg(final float ax, final float ay,
                                    final float bx, final float by) {
          final double angleRad = Math.atan2(ay - by, ax - bx);
          double angle = Math.toDegrees(angleRad);
          if (angleRad < 0) {
              angle += 360;
          }
          return (float) angle;
      }
docs: Returns angle in degrees between two points
  
  @param ax x of the point 1
  @param ay y of the point 1
  @param bx x of the point 2
  @param by y of the point 2
  @return angle in degrees between two points