Spherical Lines: Great Circles and Poles
- Author:
- Steve Phelps
Every point on the sphere can be associated with a great circle. From point A, construct a line through the center of the sphere. Then, construct a plane perpendicular to this line through the center of the sphere. The intersection is the great circle associated with the point A. Point A is called the pole of the great circle. Every great circle has two poles (do you see why?)