Respuesta :

to work out the circumference you have to multiple pi by the diameter . since pi is 3 and the diameter is 9. you have to multiply 9 by 3 to work it out.the answer would be 27. hope this helps you
texaschic101
circumference of a circle formula : C = 2 * pi * r
pi = 3
r = d/2......= 9/2 = 4.5

C = 2 * 3 * 4.5 
C = 27 cm