What is the diameter of this circle?

Answer:
diameter=18 in
radius=9 in
area=254.47 in
circumference=56.55 in
Step-by-step explanation:
Key
C=Circumference
D=Diameter
R=Radius
A=Area
π=pi=3.14159265359
Formulas
2r=d
d/2=r
πr^2=a
(2πr)=c
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