A circle has diameter = 9
Calculate Area, Circumference, Radius, Diameter
d = 2r
r = 4.5
C = 2πr
C = 2π * 4.5
C = 9π or 28.2743
A = πr2
A = π * 4.52
A = 20.25π or 63.6173
An Automated Online Math Tutor serving 8.1 million parents and students in 235 countries and territories.