On Jan 6, 8:45 pm, "warden [Andrew Leach - Maps API Guru]" <[email protected]> wrote: > Isn't it? I'm not sure who your "No" was directed to.
It was directed at Markw65, who said that "The spherical "triangle" is just a line". By definition, this is not a spherical triangle. > There *are* three great circles there, I think: part of the Prime > Meridian (0,0 to 87,0), part of the Equator (0,0 to 0,180), and part > of an oblique great circle connecting 87,0 to 0,180. Not really. 0,0 is on the Prime Meridian. 87,0 is also on the Prime Meridian. 0,180 is on the Anti-Meridian. Prime Meridian + Anti-Meridian together are one Great Circle. Usinghttp://maps.forum.nu/gm_flight_path.htmland points 85,0 to 0,180 > which lie on the map, the line goes around the Pole, on the opposite > side of the earth from the US [ie across Asia]. It doesn't follow the > Meridian. That does describe a spherical triangle. If it goes accross the pole, (and it does), it follows the meridians exactly, only that it might look funny due to the Mercator projection. > > Even if the northernmost point of the three was actually at the Pole, > there would still be two great circles involved, the Meridian and the > Equator, and a bilinear segment of a quarter of the Earth would > result. There are, in fact two great circles involved, but still all three points lie on the same great circle, (Prime Meridian + Anti-Meridian). It's like a slice of an orange, not a triangle. In order to have a spherical triangle you need "three great circular arcs", as per the definition, or three great circles, not one, not two. :-) -- Marcelo - http://maps.forum.nu -- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
