1. Why is a full circle 360 degrees?

2. Latitude 4 Also known as parallels--never cross 4 Measure N & S of the Equator 4 0-90 degrees

4. Longitude 4 Also known as meridians 4 meet at the poles 4 Measure E & W of Prime Meridian 4 0-180 degrees

5. Latitude and Longitude 4 Explorers for most of history struggled to determine precise longitude. Latitude was calculated by observing with quadrant the inclination of the sun or of charted stars, but longitude presented no such manifest means of study

6. Problem of Longitude 4 Longitude can be found by comparing a ship’s local time to the time at the port of origin. The challenge was to find a clock that could keep time at sea.