Just as the Equator serves as the starting point for latitude, the is the starting point for longitude. It is designated as 0° longitude .
: The world’s time zones are calculated based on their distance from the Prime Meridian, often referred to as Universal Time Coordinated (UTC). meridians geography
: Every meridian is half of a "great circle." When paired with its opposite (anti-meridian), it forms a full circle that divides the Earth into two equal halves. Key Meridians Just as the Equator serves as the starting
: Paired with latitude, meridians create a geographic grid that can pinpoint any exact location on the planet. : Every meridian is half of a "great circle
| Feature | Meridians (Longitude) | Parallels (Latitude) | |---------|------------------------|----------------------| | Shape | Half-circles | Full circles | | Direction | North–South | East–West | | Length | All equal (~20,000 km) | Decrease toward poles | | Number | 360 (180E + 180W + 0°) | 180 (90N + 90S + 0°) | | Parallelism | Converge at poles | Always parallel |