what exactly does "degrees , minutes and seconds of arc" mean?

Question

pertains to latitude and longitude

Answer 1

These are units used to measure circles (since lines of latitude and longitude are actually circles drawn on the earth). There are 360 degrees in a circle, 60 minutes to a degree, and 60 seconds to a minute (same as a clock, actually). For latitude, 0 degrees is the equator, and distance is measured to 90 degrees north (North Pole) and 90 degrees south (South Pole). For longitude, 0 degrees is the prime meridian (which passes through Greenwich, England), and distance is measured 180 degrees east and west from there.

I don't know why latitude is only measured to 90 degrees, but that's how it was set up (check a globe or atlas and you'll see).

Answer 2

a circle ie a complete turn is usually divided in 360 degrees. People then decided to break them down like they break down hours, namely a degree is split in 60 minutes, and each minute is split in 60 seconds.

So if someone mentions an angle of, say, 43 degrees, 15 minutes, 30 seconds, in decimal format it would be written as 43.258333 degrees.

It's a dumb system if you ask me, but it is so ingrained in the habits, at least to measure longitude and latitude, that I doubt it will change any time soon.

Hope this helps

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Answer 3

Degrees, minutes and seconds of arc always refer to angular measurement, be it longitude or lattitude or a common circle.

There are 360 degrees in a circle, 60 arc minutes in a degree and 60 arc seconds in an arc minute.

For example in astronomy, the apparent width of the moon as seen from the earth is 1/2 a degree (or 30 arc minutes).

Answer 4

180 degrees of arc from pole to pole (latitude).
90 degrees of arc from pole to the equator (also latitude).

Longitude is measured in degrees of arc east and west from the Greenwich Meridian (near London, England). There are 360 degrees from Greenwich around the globe and back to Greenwich.

There are 60 minutes in a degree, and 60 seconds in a minute.

Answer 5

actually, i think of the quote is "each and every sixty seconds you spend upset is a minute of happiness lost." It ability that in case you spend time living on hurtful issues, you're lacking out on what could make you chuffed.

Answer 6

they are used to pinpoint exact location on the earth.