You are being asked to make π the subject in
[tex]C=2πr \:[/tex]
So divide both sides of the equation by
[tex]2r[/tex]
That is
[tex] \frac{ C}{2r} = \frac{2πr}{2r} [/tex]
The you have
[tex] \frac{ C}{2r} = \pi[/tex]
or
[tex] \pi = \frac{ C}{2r}[/tex]
I hope this is helpful?
