180º (180 degrees)
= ½ way around Earth: to the exact opposite point*
180º is the furthest apart any one location on Earth’s surface can be
from another surface location.
* the Antipode
(or “antipodal point”)
basic discussion with different, in some ways simpler images
But Please Note: On this web site, “degrees” or “ º ” generally refers to distance along a diagonal line, rather than a line of latitude or longitude: As with the great majority of locations on Earth: most are at different longitudes and latitudes from each other.
In such instances, one speaks of the arc distance between two points on Earth’s surface, measured in angular degrees.
One angular degree is very close to 69 miles everywhere on Earth’s surface.
(Although such angular distances converted to miles or kilometers can vary slightly in different regions (especially near the poles where Earth is slightly flatter)..
(the maximum variation in a degree of latitude is 0.7 miles (1%):
68.7 to 69.4.
according to this page
(Longitude is quite a different story, of course, as the linked page notes: Since lines of longitude converge at the poles, the distance of one degree of longitude decreases the closer a location is to one of the poles, from 69 miles at the equator down to nothing at either pole.)