Answer:
Half of 16 is 8 which is your radius,
8 x 3.14(pi) x 2(you always have to use this number because you just need it when solving circumference) = 50.24
Explanation:
Formula of circumference:
radius(half of diameter or given radius) x pie/pi some people call it (3.14 or 22/7 use what is supposed to be used) x 2 (always 2)