What is the circumference of each of the following circles? (Take pi = 3.14)

Rediasi ya duara ya kwanza ni $r = 2.45 \text{ cm}$.

Mzingo wa duara a) ni $\boxed{\text{15.386 cm}}$.

Rediasi ya duara ya pili ni $r = 4.2 \text{ cm}$.

Mzingo wa duara b) ni $\boxed{\text{26.376 cm}}$.

Rediasi ya duara ya tatu ni $r = 10 \text{ cm}$.

Mzingo wa duara c) ni $\boxed{\text{62.8 cm}}$.