Re: What is the EXACT circumference of the Earth (both equatorial and polar)?

To within a kilometre, the equatorial circumference of the Earth is 40077 km, and 
the polar circumference is 40005 km. Measuring to the nearest metre is more 
problematic. At one stage, the polar circumference was 40000.000 km, because the 
metre was defined for a brief period as one ten-thousandth of the length of a 
half meridian. But the length of the metre has changed since then.

The real problem with measuring to the nearest metre is that the length you get 
is going to depend on whether you make your tape measure go up over all the 
mountains, or whether you dig a little trench so that it can go around the world 
at sea level. It is also going to depend on whether you pull it very tight, or 
leave it slack so that it can go up and down the walls of the crevasses at the 
edge of the Antarctic continent, when you are measuring the polar circumference. 
For the equatorial circumference, on the other hand, it will depend on how badly 
your measure gets tangled in the branches of the Orinoco jungle ;-)