Converting Earth's radius to circumference in kilometers

[Darkhrse99]

I need to convert the Earth's radius of 6.37 x 10^6 into the km, But I need it to be the circumference in km.


I started out with 6.37x 10^6 times (1km/1000m) which gives me 6.37x 10^3. Now I need to convert to the circumference, but not sure how. The answer is 4.00x10^4. I don't see how 6.37x10^3 is going to come close to the answer. Where do I go from here?

Thanks
Jason

 

[Borek]

What is the formula for a circumference?

 

[Darkhrse99]

What is formula for circumference?

I don't know?

 

[Borek]

I find it hard to believe that you were not taught it earlier. But if not - check in your textbook, handbook or in wikipedia, or just google it.

 

[Darkhrse99]

Sorry about that. I found the formula. I wasn't thinking right. By using that formula 6.37x10^3 times Pi equals 2.0000. Than i multiplied it by 2 and got 4.00x10^4.