[Quasi-OT] Maths/Geography Question

[SableWyvern]

Information I need for the purposes of world building:

Assume the world is a perfect sphere with a circumference of 10,000km.

What is the distance from one fixed point at Latitude 72 degrees, back to that same point, following the parallel around?

Many thanks in advance.

 

[SableWyvern]

Oh, and while I'm on the topic, could someone confirm for me that the parallels are equidistant?

 

[CobaltGrC]

Ermm.. yeah parrellels are equal distance.. on earth one degree of lat is about 111 km.

 

[Heretic Apostate]

Multiply 10,000 km by the Cosine of the angle. That'll give you the "circumference" at that point.

 

[SableWyvern]

OK. That gives me approx 3090, if I did it right.

Thanks.

 

[CobaltGrC]

Alright I'm going to take a stab at this:

To find the Length of Longitude = cos(lat) * Length of Lat

I divided 10,000km/360 degrees to get 1 degree of Lat, which is roughly 27.7(repeating)km (your planet is MUCH smaller then earth) I then take this number and plug it in with the degree you want messured.

cos(72) * 27.7 to = about 8.55 km, then I take 8.55 km and * by 360 degree to get 3078km...

So I believe the answer you need is 3078km... anyone want to double check if I'm doing this right? This is only my first year into my study to get my geography major, so I could be doing this wrong..

 

[SableWyvern]

Oops.

Huge error on my behalf.

Circumference should be 40,000km. Forgot to multiply by 4 (10,000km being north pole to equator via Paris).

Edit: thus, new distance is 12,360km.

BTW cobalt, your /360 at the start, followed by x360 at the end is redundant. Apart from that, your method is the same as what Heretic Apostate suggested.

 

[CobaltGrC]

Yeah, but atleast we are all trying to help you towards your goal.

 

[SableWyvern]

Yes, that is appreciated. I didn't intend to imply otherwise.

 

[MeepoTheMighty]

Slight hijack.....

Why is it that in Britian/Australia, you guys call it "maths," and in America, we call it "math?"