One degree of latitude (north or south) equals 60 nautical miles. One degree of longitude (east-west) is approximately 60 nautical miles times the cosine of the mid-latitude.
So 5 degrees is something less than 300 NM, depending on the heading and the latitude.
130 degrees approximately
It is the path along a circle that cuts the earth into two equal hemispheres.
60
Much bigger and better than a regular circle... But seriously, a great circle on a sphere is a circle that runs along the surface of that sphere and cuts it into two equal halves. It is the largest circle that can be drawn on a given sphere. The center of any great circle is the center of the sphere.
The half circle of 180 degrees of arc connecting the Earth's poles is known as a great circle. This is the largest circle that can be drawn on a sphere and it divides the sphere into two equal hemispheres.
No. You have to cross 360 degrees of meridian for a great circle, so 180 degrees East plus 180 degrees West around the equator will form a great circle.
Two meridians can form a great circle when they are 180 degrees apart, as they represent opposite points on the Earth's surface. For example, the Prime Meridian at 0 degrees and the Antimeridian at 180 degrees are such meridians. Any two meridians that are 180 degrees apart will create a great circle, which is the largest circle that can be drawn on the surface of a sphere.
The great circle at 0 degrees latitude is known as the Equator. It is an imaginary line that divides the Earth into the Northern Hemisphere and the Southern Hemisphere.
eQuator forms a great circle because it is a circle created by the intersection of a sphere and a plane that passes through the center of the sphere. The equator of the Earth, for example, is a great circle because it divides the Earth into two equal halves. The shortest path between any two points on a great circle is along the circle itself.
The Equator
equator
That's called a "great circle" of the sphere. -- It's any circle whose center is at the center of the sphere. -- Its diameter is equal to the diameter of the sphere. -- Its area is equal to 1/4 the surface area of the sphere. -- The shortest distance between any two points on the sphere is along the piece of the great circle on which they lie. (There's only one, unless the two points are the opposite ends of a diameter.)