When backing up it is necessary to look back as long as you sound your horn?

This statement emphasizes the importance of being aware of your surroundings while reversing, particularly when using your vehicle's horn as a warning signal. Sounding the horn alerts others nearby to your presence, allowing you to back up safely. However, it is crucial to also physically check your surroundings to avoid potential hazards. Ultimately, a combination of auditory and visual awareness is essential for safe backing maneuvers.