Respuesta :

Formula for the circumference of a circle:

C = 2πr     (C = circumference      π(pi) = 3.14.....    r = radius)

You know:

r = 9 cm      

π = 3.14       So substitute/plug it into the equation

C = 2πr

C = 2(3.14)(9)

C = 56.52 cm      

Answer:

56.55

Step-by-step explanation:

C=2πr=2·π·9≈56.54867cm