Here's why:
* Longitude lines run from North Pole to South Pole. There are an infinite number of lines you could draw, each with a different longitude.
* We use 360 degrees as a standard way to measure the distance around a circle. This is why we divide the Earth's circumference into 360 degrees of longitude.
* The Prime Meridian is the line of longitude at 0 degrees, and the International Date Line is at 180 degrees. This divides the globe into the Eastern and Western hemispheres.
So, while there are 360 degrees of longitude, they are not all physically drawn on the globe. We use the system to precisely locate any point on Earth.
