Editing Circular orbit (section)

==Equation of motion==
The [[orbit equation]] in polar coordinates, which in general gives ''r'' in terms of ''θ'', reduces to:{{clarify|reason=There is no θ in motion equation!|date=January 2016}}{{cn|date=August 2019}}
:<math>r={{h^2}\over{\mu}}</math>
where:
*<math>h=rv</math> is [[specific angular momentum]] of the orbiting body.

This is because <math>\mu=rv^2</math>