The circunference C is given by
[tex]C=2\pi\cdot r[/tex]
where Pi is given by
[tex]\pi=3.1416[/tex]
and r (radius) is equal to 1 units (in our case).
By substituting these values into the circunference formula, we get
[tex]C=2(3.1416)(1)[/tex]
which gives
[tex]C=6.2832[/tex]
that is, the circunferece is equal to 6.2832 units.
