# Definition:Pole of Great Circle

## Definition

This is a special case of the pole of a circle.

Let $S$ be a sphere whose center is $O$.

Let $C$ be a great circle of $S$.

Let $AB$ be the diameter of $S$ situated perpendicular to the plane of $C$.

The points $A$ and $B$, where the diameter intersects $S$, are the poles of the great circle $C$.