How do you find the radius and diameter with the circumference

Ok

relation of diameter to radius

2 radius=1diameter

radius=1/2 diameter

2r=d

d/2=r

circumfernce=2pir

since 2r=d

circumference=2d

so

c=pid=2pir

so if ou have circunference and you want to find diameter and radius

c=pid

divde both sides by pi

c/pi=d

c=2pir

divide both sides by 2pi

c / (2pi) = r

so

r=c / (2pi)

d=c/pi