USA Coordinate Systems Basics Quiz
Understand latitude, longitude, and decimal degrees in the context of the USA (10 questions).
USA Coordinate Systems Basics Quiz: Quick Study Notes
Mastering coordinate systems is fundamental to understanding geography, especially when studying the United States. This section provides quick notes on latitude, longitude, and decimal degrees, essential for navigating and mapping the country.
Core Concepts Explained
Measures North or South position relative to the Equator (0°). Lines of latitude are called parallels.
Measures East or West position relative to the Prime Meridian (0°). Lines of longitude are called meridians.
A simple format for coordinates, representing fractions of a degree. Easier for digital mapping than DMS (Degrees, Minutes, Seconds).
All of the United States lies in the Northern Hemisphere (positive latitude) and the Western Hemisphere (negative longitude).
Key Takeaways
- Latitude lines run east-west and measure north-south distance from the Equator.
- Longitude lines run north-south and measure east-west distance from the Prime Meridian.
- The Equator is 0° latitude, and the Prime Meridian is 0° longitude.
- Decimal degrees express latitude and longitude as single numbers, simplifying calculations.
- For locations in the USA, latitude values are positive, and longitude values are negative.
- Understanding coordinate systems is crucial for GPS, mapping, and GIS applications.
Frequently Asked Questions
What is latitude?
Latitude is a geographic coordinate that specifies the north-south position of a point on the Earth’s surface. It is measured in degrees, from 0° at the Equator to 90° North or South at the poles.
What is longitude?
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth’s surface. It is measured in degrees, from 0° at the Prime Meridian to 180° East or West.
Why are decimal degrees used?
Decimal degrees (DD) simplify the representation of geographic coordinates by expressing degrees, minutes, and seconds (DMS) as a single decimal number. This format is more convenient for digital calculations, mapping software, and GPS devices.
Do US coordinates always have negative longitude?
Yes, for locations in the United States, longitude values are always negative. This is because the contiguous U.S., Alaska, and Hawaii are all situated in the Western Hemisphere, which uses negative values for longitude.
What’s the primary difference between latitude and longitude?
The primary difference is the direction they measure: latitude measures distance north or south of the Equator, while longitude measures distance east or west of the Prime Meridian. Latitude lines are parallel, while longitude lines converge at the poles.

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