Can someone help me with this circle geometry problem (question 1) ty

Step-by-step explanation:
1. Radius=3cm, diameter=6cm
Circumference=3.14×6cm=18.84cm
2. Radius=6in, diameter=12in
Circumference=3.14×12in=37.68in
3. Radius=9mm, diameter=18mm
Circumference=3.14×18mm=56.52mm