Respuesta :

Hello!

The circumference is the diameter multiplied by pi. 

a. 18[tex] \pi [/tex] in.

The area is the radius (half the diameter) squared multiplied by pi. This gives us our answer below.

b. 81[tex] \pi [/tex] in.²

I hope this helps!
Circumference of circle formula: C = 2πr
Area of circle formula: A = πr²
Note that π = 3.14

Diameter of the circle = 18
To find radius, divide 18 with 2

18/2 = 9

Radius = 9
Plug in 9 for r.

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Circumference of Circle

C = 2πr
C = 2π(9)
Simplify. combine terms
C = 18(3.14)
C = 56.52 in²

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Area of circle:

A = πr²
A = π(9)²

9 x 9 = 81

A = 81π

81 x 3.14 = 254.34

A = 254.34 in²

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hope this helps