How to get the rotation angle in degrees?

Question

Java

How to learn the angle of rotation in degrees? Connected accelerometer and magnetic field sensor. Each sensor gives 3 values.

float[] valuesAccel = new float[3];
float[] valuesMagnet = new float[3];
float[] valuesAccelGravity = new float[3];
public void onSensorChanged(SensorEvent event) {
            switch (event.sensor.getType()) {
                case Sensor.TYPE_ACCELEROMETER:
                    for (int i = 0; i < 3; i++) {
                        valuesAccel[i] = event.values[i];
                        valuesAccelGravity[i] = (float) (0.1 * event.values[i] + 0.9 * valuesAccelGravity[i]);
                        valuesAccelMotion[i] = event.values[i]
                                - valuesAccelGravity[i];
                    }
                    break;
                case Sensor.TYPE_MAGNETIC_FIELD:
                    for (int i=0; i < 3; i++){
                        valuesMagnet[i] = event.values[i];
                    }
                    break;
            }

        }
 void getDeviceOrientation() {
        SensorManager.getRotationMatrix(r, null, valuesAccel, valuesMagnet);
        SensorManager.getOrientation(r, valuesResult);

        valuesResult[0] = (float) Math.toDegrees(valuesResult[0]);
        valuesResult[1] = (float) Math.toDegrees(valuesResult[1]);
        valuesResult[2] = (float) Math.toDegrees(valuesResult[2]);
        return;
    }

I need to get the angle of rotation from a given point, that is, we get up, look in one direction, then turn around and look in the other direction, this is the angle I need. What data to use for this? just started working with sensors.