On Monday 23 March 2009 18:59:03 James R. Frysinger wrote: > I don't think that radians are going to go away in either of our > lifetimes. It's one of the derived units that physicists and many > engineers are fond of.
Mathematicians too. All trigonometric functions are naturally defined with the angle in radians. In my work, angles are expressed in degrees, minutes, and seconds. Why DMS instead of decimal degrees or gons I do not know, but they are measured with a theodolite that divides the circle into some large round integral number of parts. For expressing bearings and azimuths, radians would not make sense; there would be an odd-sized interval just before 0. But I have to use radians, because, on some older maps, curves are labeled with radius and length but not angle or delta. To figure the delta (those old curves are almost always tangent at both ends), I divide the length by the radius. That's the delta in radians. Then I add or subtract that to the starting bearing, which is in DMS. So I convert the delta to DMS. I've done this enough that I have a radian in seconds memorized. It's 206264.8, and its reciprocal is 4.848137e-6. Pierre
