Either is understandable. Traditionally, the absence of a plus sign means a positive number anyway.
Depends on how you count it. If you take it as 90 degrees north and 90 degrees south, that's 180 degrees of latitude. Looking at just one hemisphere, then just 90 degrees will do it.
There is a 30 degrees line of latitude north of the Equator (just above the Tropic of Cancer), and a 30 degrees line of latitude south of the Equator (just below the Tropic of Capricorn). So 30 degrees latitude appears in both the Northern Hemisphere, and the Southern Hemisphere.
The Equator is at 0 degrees latitude. The South Pole is at the centre of the Southern Hemisphere. The South Pole is at 90 degrees S latitude. Every line of latitude between 0 and 90 S are in the Southern Hemisphere.
Indiana extends from (just south of) 38 degrees north to (just south of) 42 degrees north. The full degree latitude closest to the midpoint is 40 degrees north.
a latitude line is a line going from east to west. Just like the equator. the equator is a latitude line measuring at ) degrees latitude.
The Geographic Poles are just points; 90 Degrees North or South Latitude.
Canada. Note that that is just one point in Canada, which is a big country, stretching over many degrees of latitude and longitude.
Yes, California lies south of 40 degrees latitude. The northernmost point of California is just above 42 degrees latitude, while the majority of the state extends southward well below 40 degrees. This places all of California within the southern hemisphere relative to the 40-degree latitude line.
360 - it is just an imperfect circle
That's less than ten degrees from the Arctic Circle.
Just outside Forsyth, Georgia
The latitude of the line that is two-thirds of the way from the equator towards the south pole is approximately -45 degrees. This is because the latitude of the equator is 0 degrees and that of the south pole is -90 degrees, so two-thirds between them corresponds to -45 degrees.