# Great Circle

**GREAT CIRCLE**. The circle in which a Sphere is cut by a plane is called a " great circle," when the cutting plane passes through the
centre of Sphere. Treating the earth as a Sphere,
the meridians of longitude are all great circles. Of the parallels of latitude, the equator only is a great circle. The shortest line joining any two points is
an arc of a great circle. For " great circle sailing " see NAVIGATION.

*Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)*