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Re: A triangle on the equator
From: David Pike
Date: 2025 Oct 10, 13:36 -0700
From: David Pike
Date: 2025 Oct 10, 13:36 -0700
Lars Bergman you wrote: “your value of the earth's circumference through the poles seems to be some 62 km too small.”
That’s correct. It should be 40008km. I got 39946km from that caption which comes up first when you ask Google a question, so I must have asked the wrong question.
Recalculating, my result for angle A should be:
A=arc tan((8x40075xcos0.1°)/(6x40008)) = 53°10.56’. Forgetting about the cos0.1° makes about 0.01 of a minute's difference.
Frank Reed. I looked for the tables you talked of, but I struggled to find them online. I presume they were similar to the 'SAC Tables' some will remember being issued with for calculating radar offsets in yds/ft (I can't remember which) from dlat & dlong for use with H2S. DaveP
