What is the approximate longitude measurement of the international date line?

The international date line is located at approximately 180° longitude. This line serves as the demarcation point where one calendar day ends and the next begins. It runs from the North Pole to the South Pole, zigzagging around various territories and islands to ensure that populations remain in the same time zone as their land.

Understanding the significance of the international date line involves recognizing that it allows for a consistent system of timekeeping across the globe. By maintaining this line at 180° longitude, it effectively creates a clear boundary for the world, making it easier to manage time zones and coordinate international travel and communication.

The other options are incorrect because they represent other significant longitudinal points: 90° longitude is in the middle of the United States, 270° longitude is essentially equivalent to -90° longitude in the Western Hemisphere, and 0° longitude is the Prime Meridian, which passes through Greenwich, England. None of these points serves the same purpose or function as the international date line.