What is the great circle route?

• A. The shortest distance across the surface of a sphere between two points on the surface.
• B. The longest distance around the equator.
• C. The path a plane takes when circling a waypoint.
• D. A straight line on a flat map projection.

Answer: (A)

The great circle route is the shortest distance across the surface of a sphere between two points. It’s the arc of a circle formed when a plane passes through the sphere’s center and the two points, so this path minimizes surface distance on Earth. On a globe it looks like a straight line, but on most flat maps it appears curved because map projections distort distances and directions. This is why long flights are planned along these routes to reduce travel distance, even though the line may bend on a chart. The other options don’t fit because the longest distance around the equator isn’t the rule for shortest travel between two points, circling a waypoint isn’t about the shortest surface path, and a straight line on a flat map isn’t generally the true shortest path on a sphere.