Geosychoronous Satellites and their KE/Orbitals

[AryRezvani]

Homework Statement

Prove that the product of the kinetic energy and orbital radius of a geosynchronous satellite is constant.

Homework Equations

Not sure on the orbital radius part

KE=KE = ½mGM/R

The Attempt at a Solution

I'm lost on where to begin. How exactly would I 'prove' it?

 

[AryRezvani]

Bump!

 

[gneill]

What shape must an orbit have if it is geosynchronous?