To measure longitude, where should you place one point of a divider?

To measure longitude, where should you place one point of a divider?

• A. The Equator
• B. The longitude line nearest the object
• C. The Prime Meridian
• D. The latitude line nearest the object

Answer: (B)

Longitude is defined by lines of longitude (meridians), which are the vertical reference lines on a chart. To determine how far east or west you are from the Prime Meridian, you start by anchoring one point of the divider on the meridian that passes closest to the object. This gives you the correct meridional reference for that position. You can then move the other point to the Prime Meridian or use the chart’s longitude scale to read the angular distance. Placing the divider on the Equator or on a latitude line would measure along a circle of latitude, not along a meridian, so it wouldn’t yield the longitude. Therefore, the best starting point is the longitude line nearest the object.

Longitude is defined by lines of longitude (meridians), which are the vertical reference lines on a chart. To determine how far east or west you are from the Prime Meridian, you start by anchoring one point of the divider on the meridian that passes closest to the object. This gives you the correct meridional reference for that position. You can then move the other point to the Prime Meridian or use the chart’s longitude scale to read the angular distance. Placing the divider on the Equator or on a latitude line would measure along a circle of latitude, not along a meridian, so it wouldn’t yield the longitude. Therefore, the best starting point is the longitude line nearest the object.