Best Answer

Circumference of any circle is:

C = (pi)/d

where

C is circumference

d is diameter

.

Area of any circle:

A = (pi)r^2

where

A is area

r is radius

.

Of course, radius is half the diameter or

r = d/2

Pulling it all together:

Since they gave you circumference, use the circumference formula to find d (diameter):

C = (pi)/d

18(pi) = (pi)/d

18=d

.

Extract radius (r):

r = d/2

r = 18/2

r = 9 cm

.

plug it into the formula for area of a circle:

A = (pi)r^2

A = (pi)9^2

A = 81(pi) square cm (this is what they're looking for)

OR

Circumference = 2piR = 18pi

R = 9

Area = piR^2 = 81pi

Q: What is the area of a circle with the circumference of 18 pi?

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circumference = pi*18 cm area = pi*92 square cm

If pi is taken as 3.14 then:- Circumference of the circle = pi*18 units Area of the circle = pi*92 square units

Circumference of a circle = 2*pi*radius or diameter*pi Area of a circle = pi*radius2

Circumference of a circle: 2*pi*radius or diameter*pi

Area of a circle = pi*radius2 Circumference of a circle = 2*pi*radius or pi*diameter

Related questions

circumference = pi*18 cm area = pi*92 square cm

If pi is taken as 3.14 then:- Circumference of the circle = pi*18 units Area of the circle = pi*92 square units

Circumference of a circle = 2*pi*radius or diameter*pi Area of a circle = pi*radius2

Circumference of a circle is (pi * diameter). Area of a circle is (pi * r2).

Pi is the number of times the diameter of a circle will fit into the circumference. Pi is not a circle, and does not have a circumference or area. To calculate a circumference USING pi, the circumference is diameter * pi. To find the area using pi, area = pi * radius * radius

Circumference of a circle = 2*pi*radius or diameter*pi Area of a circle = pi*radius squared

Pi is related to the area and the circumference of the circle. The area is Pi multiplied by the radius of the circle squared and the circumference is Pi times the diameter of the circle. if you're wondering how it works, pi is the area of a circle with radius of 1 (unit), and the circumference of a circle with a radius of ½ (unit).

Circumference of a circle: 2*pi*radius or diameter*pi

Area of a circle = pi*radius2 Circumference of a circle = 2*pi*radius or pi*diameter

Area = (Circumference squared)/4 pi Circumference = 2 sqrt(Area times pi)

Circumference = 36*pi

The formula for the area of a circle is pi * radius squared. The circumference of a circle's formula is pi * diameter. NOTE: pi equals approx. 3.14