The 180th longitude line is commonly known as which geographic boundary?

The 180th longitude line is commonly known as which geographic boundary?

• A. Prime Meridian
• B. International Date Line
• C. Equator
• D. Tropic of Cancer

Answer: (B)

Lines of longitude run from the North Pole to the South Pole and measure how far east or west you are from the Prime Meridian at 0° longitude. The line directly opposite that, at 180° longitude, is known as the International Date Line. Its main role is in timekeeping: crossing it changes the calendar date. The other two options are different kinds of lines— the Prime Meridian is 0° longitude, the Equator is 0° latitude, and the Tropic of Cancer is a latitude around 23.5°N.

Lines of longitude run from the North Pole to the South Pole and measure how far east or west you are from the Prime Meridian at 0° longitude. The line directly opposite that, at 180° longitude, is known as the International Date Line. Its main role is in timekeeping: crossing it changes the calendar date. The other two options are different kinds of lines— the Prime Meridian is 0° longitude, the Equator is 0° latitude, and the Tropic of Cancer is a latitude around 23.5°N.