The MPU-6050 is a rate gyro, and measures the rate of rotation, not angles.
You can use the accelerometer to measure the two stationary tilt angles, as described here: How_to_Use_a_Three-Axis_Accelerometer_for_Tilt_Sensing-DFRobot
All the details are in the device data sheet: https://invensense.tdk.com/wp-content/uploads/2015/02/MPU-6000-Datasheet1.pdf