# a question about the geodesic circle

How to show that the geodesic circles have constant geodesic curvature on a surface of constant curvature?

Thanks

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Well, the obvious thing to do is to take geodesic polar coordinates. Have you tried that? You should be able to prove that constant Gaussian curvature forces the metric to take a particular form, and this will in turn imply that geodesic circles have constant geodesic curvature. –  Zhen Lin May 11 '11 at 14:14
@Zhen Lin: Why is it not possible to simply/algebraically express geodesic curvature in terms of Gaussian curvature and $u_0$? koletennbert's question has not yet been answered. math.stackexchange.com/questions/162474/… –  Narasimham Sep 25 '14 at 4:30
I expected to arrive at a result maybe somewhat like $u_0 K +1/u_0.$ –  Narasimham Sep 25 '14 at 5:04