A circle on the Earth's surface that divides the Earth into two equal halves.

A circle on the Earth's surface that passes through the Earth's center.

A circle on the Earth's surface that is perpendicular to the Earth's axis.

A circle on the Earth's surface that is parallel to the Earth's equator.

A circle on the Earth's surface that divides the Earth into two unequal halves.

A circle on the Earth's surface that passes through the Earth's center.

A circle on the Earth's surface that is perpendicular to the Earth's axis.

A circle on the Earth's surface that is parallel to the Earth's equator.

Great circles are larger than small circles.

Great circles pass through the Earth's center, while small circles do not.

Great circles divide the Earth into two equal halves, while small circles divide the Earth into two unequal halves.

All of the above.

The equator

The prime meridian

The Tropic of Cancer

The Tropic of Capricorn

All of the above

The parallels of latitude

The meridians of longitude

The Arctic Circle

The Antarctic Circle

All of the above

A straight line

A great circle

A small circle

It depends on the location of the two points

The distance along a straight line between the two points

The distance along a great circle between the two points

The distance along a small circle between the two points

It depends on the location of the two points

Use the Pythagorean theorem

Use the law of cosines

Use the haversine formula

Use the Vincenty formula

The shortest distance between the two points

The longest distance between the two points

The most direct route between the two points

The least direct route between the two points

Navigation

Surveying

Cartography

Astronomy

All of the above

$$x^2 + y^2 + z^2 = R^2$$

$$x^2 + y^2 - z^2 = R^2$$

$$x^2 - y^2 + z^2 = R^2$$

$$x^2 - y^2 - z^2 = R^2$$

$$x^2 + y^2 + z^2 = r^2$$

$$x^2 + y^2 - z^2 = r^2$$

$$x^2 - y^2 + z^2 = r^2$$

$$x^2 - y^2 - z^2 = r^2$$

The angle between the two planes that contain the great circles

The angle between the two lines that intersect the great circles at right angles

The angle between the two lines that are tangent to the great circles at the same point

The angle between the two lines that are parallel to the great circles at the same point

The angle between the two planes that contain the great circle and the small circle

The angle between the two lines that intersect the great circle and the small circle at right angles

The angle between the two lines that are tangent to the great circle and the small circle at the same point

The angle between the two lines that are parallel to the great circle and the small circle at the same point

The angle between the two planes that contain the small circles

The angle between the two lines that intersect the small circles at right angles

The angle between the two lines that are tangent to the small circles at the same point

The angle between the two lines that are parallel to the small circles at the same point