Answer:
the 3 cm is the radius, if you multiply the radius by 2 you get the diameter, which is 6 cm in this case. If you use the formula for the circumference of a circle (diameter x pi = circumference) (circumference is distance around the circle) you get 6 x pi = 18.85 (note: 18.85 is not exact but rounded to 2 decimal points)
So the distance around the circle is 18.85 cm