# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

**Re: Mathematical Question**

**From:**Robert Eno

**Date:**2002 Sep 19, 23:18 -0400

This is going to be a tough one! I don't mean a spherical triangle but you are all on the right track... Let's say you were to start at the north pole of a sphere and then excised the portion of the sphere from 90 degrees to 80 degrees. Now let's say you are just excising the surface portion. It would have a spherical surface but would be lens shaped. I'm starting to confuse even myself. ----- Original Message ----- From: Vic FraenckelTo: Sent: Thursday, September 19, 2002 9:47 PM Subject: Re: Mathematical Question > Is this not a spherical triangle? Prehaps I misunderstand your description? > > Vic > ________________________________________________________ > > Victor Fraenckel - The Windman vfraenc1{at}nycap.rr.com > KC2GUI www.windsway.com > > Home of the WindReader Electronic Theodolite > Read the WIND > > "Victory at all costs, victory in spite of all terror, victory however long > and hard the road may be; for without victory there is no survival." > - Winston [Leonard Spencer] Churchill (1874 - 1965) > > Dost thou not know, my son, with how little wisdom the world is governed? > -Count Oxenstierna (ca 1620) > > ----- Original Message ----- > From: "Robert Eno" > To: > Sent: Thursday, September 19, 2002 9:09 PM > Subject: Re: Mathematical Question > > > | Ok, let's say that it has a lensatic shape and a circular base. What would > | it be called? > | > | I may have erred in my description. I guess and arc is two dimensional > | whereas it's spherical equivalent would be three dimensional. > | > | > | ----- Original Message ----- > | From: Brian Whatcott > | To: > | Sent: Thursday, September 19, 2002 9:02 PM > | Subject: Re: Mathematical Question > | > | > | > At 07:30 PM 9/19/02, you wrote: > | > >Greetings list, > | > > > | > >Given the rather esoteric nature of some of the recent discussions, I > am > | > >hopeful that one of you will have the answer to a long-standing > question > | > >of mine. > | > > > | > >What is the term used to describe a small 2 dimensional section of a > | > >sphere? Or to put it another way, if a small section of a circle is > | called > | > >an "arc", what is the equivalent in a sphere? > | > > > | > > | > A spherical surface may have an irregular perimeter, or be a > | > spherical triangle, or spherical polygon, or a spherical segment of one > | base > | > according to > | > Math Dictionary, James & James, Van Nostrand. > | > > | > > | > > | > Brian Whatcott > | > Altus OK Eureka! > | > > | >