The circumference for a circle is identified as pi × 2 × radiant
the radiant is half the diameter
therefore, the radiant is 6 u.o.l.
we can apply this into for the circumference of the circle. which should be:
pi x 2 x 6
= 12×pi
If we assume pi ~ 3.14
3.14 × 12 = 36 + 1.2 + 0.48 = 37.20 + 0.48= 37.68 u.o.l
Remark:
u.o.l is unites of length because you didn't identify the specific length of the circle.
Hence, the answer is 37.68 u.o.l if we supposed pi ~ 3.14