It's alright, you're not stupif. It's just a little bit complicated if it's either your first time doing it or has been a while since you did it last.
r: 16 km. d: 32 km.
The Formula is: C = 2πr. Because it says below the rest of the data that we use 3 for pi, and since we have r, which is 16, the equation becomes C = 2(3)(16).
The answer becomes 96 Kilometers.
