Suppose I know city A is located at latitude 21 degrees exactly and city y is located at latitude 24 degrees exactly. I know the distance between the two cities is 400 kilometers.(adsbygoogle = window.adsbygoogle || []).push({});

I want to find the circumference of the earth approximately

How do I do this?

My feeling is that we

subtract the two latitudes to find 24-21 = 3 degrees

so 3 degrees corresponds to roughly 400 kilometers (1)

so 180 degrees of latitude corresponds roughly to X kilometers (2)

and I find that x = 24000 kilometers

is line (1) and (2) correct or should the second line read

360 degrees of latitude corresponds roughly to X kilometers??

thanks

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# Circumference of the earth via latitute mesurement

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