All the way around anything that's measured in angles is typically 360 degrees,
and the earth is no exception.
1 degree = 60 arc minutes so 0.5 degrees of latitude or longitude is 30 arc minutes.https://en.wikipedia.org/wiki/Minute_and_second_of_arc
A meridian describes an arc connecting the north and south poles (a single line of longitude). As such, a meridian will be 180 degrees.
That's exactly the same as asking "How many different lengths are there on a piece of rope ?" There's no limit to the possible number of different latitudes. If you name two different latitudes, then no matter how close together they are, I can always name a new one that's in between yours.
Degrees, Minutes and Seconds of arc. Same as longitude.
That will depend on the length of the arc but an arc radian of a circle is about 57.3 degrees
-- Distance is never expressed in degrees. -- The angle of the arc on the Earth's surface between the Prime Meridian and a location of interest is the location's longitude. It may be expressed in any units of angle.
180x2= 360 degrees
"Lines of longitude" are conceptual, not physical; there can be as many as we want. For example, there are 3600 "seconds of longitude" between each degree of longitude. That's 60 minutes of arc per degree, and 60 seconds of arc per minute.
Just "degree", not "arc degree". A degree has 60 minutes; therefore, to convert from degrees to minutes, you multiply by 60.
One arc second is one 3600th of a degree.
(lenth of arc/circumference)*360 degrees
The complete arc of a semicircle is 180 degrees