Remember, [tex]C=\pi d[/tex], where [tex]C[/tex] is circumference and tex]d[/tex] is the diameter. They are related by a constant [tex]\pi[/tex] (pi).
We can solve the above equation for d and then substitute our known values.
[tex]C=\pi d[/tex]
[tex]d= \dfrac{C}{ \pi } = \dfrac{361 \pi }{ \pi } = 361 \ units[/tex]