Degrees, Minutes, Seconds

Date: 08/26/97 at 04:15:49
From: laura vickers
Subject: Basic trigonometry

We have just started trigonometry and they mention degrees, minutes 
and seconds. I know that degrees are what you use to measure angles 
but I thought minutes and seconds were time measurements. Are they 
fractions of a degree or something else? Do the little flicks at the 
end of an angle measurement (5*14' - the star representing a degree 
sign - have anything to do with them? If these are not minutes, what 
are they? 

One last thing - we are meant to be able to calculate the sin, cos and 
tan of the angles with the 's in them but my calculator doesn't have 
the button they say to press (o'"). On various other models of 
calculator how do you do this? 

Thanks for your help.

Laura

Date: 08/26/97 at 11:33:50
From: Doctor Marko
Subject: Re: Basic trigonometry

Hi Laura,

Yes, minutes and seconds are measures of time, but they are also the 
way one measures angles.

The conversion table is really simple and resembles that of time:

1 degree = 60 minutes (denoted 60')
1' = 60 seconds (also 60")

As far as the calculators are concerned mine (Casio fx-85n, about 5-10 
years old) has an option to input degrees, minutes, and seconds,
but you can do these problems by converting minutes and seconds
to decimal numbers of degrees. For example, 30 minutes = .5 degrees

In general, when given an angle measurement in minutes and seconds, 
you can use the formula

      x'y" = x/60 + y/3600 degrees

where x and y are numbers of minutes and seconds, respectively.

Hope that this has helped,

-Doctor Marko,  The Math Forum
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