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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
What else can I help you with?
What is the circumference and the area of a circle whose diameter is 18 cm?
circumference = pi*18 cm area = pi*92 square cm
What is pie 3.140 of circle diameter is 18?
If pi is taken as 3.14 then:- Circumference of the circle = pi*18 units Area of the circle = pi*92 square units
How do you do circumference and area?
Circumference of a circle = 2*pi*radius or diameter*pi Area of a circle = pi*radius2
What is the circumference of an 18 inch circle?
Circumference of a circle: 2*pi*radius or diameter*pi
What is the area and circumference of 12 ft?
Area of a circle = pi*radius2 Circumference of a circle = 2*pi*radius or pi*diameter
What is the circumference and the area of a circle whose diameter is 18 cm?
circumference = pi*18 cm area = pi*92 square cm
What is pie 3.140 of circle diameter is 18?
If pi is taken as 3.14 then:- Circumference of the circle = pi*18 units Area of the circle = pi*92 square units
How do you do circumference and area?
Circumference of a circle = 2*pi*radius or diameter*pi Area of a circle = pi*radius2
What is the formula for finding circumference and area of a circle?
Circumference of a circle is (pi * diameter). Area of a circle is (pi * r2).
How do you calculate circumference and area of pi?
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
How do i find circumference and area of a circle?
Circumference of a circle = 2*pi*radius or diameter*pi Area of a circle = pi*radius squared
What is the circumference of an 18 inch circle?
Circumference of a circle: 2*pi*radius or diameter*pi
How is pi in relation to a circle?
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).
What is the area and circumference of 12 ft?
Area of a circle = pi*radius2 Circumference of a circle = 2*pi*radius or pi*diameter
What is the relationship between the circumference of a circle and the area of a circle?
Area = (Circumference squared)/4 pi Circumference = 2 sqrt(Area times pi)
What is the circumference of a circle with a radius of 18 leave in pi?
Circumference = 36*pi
What is the formula for area and circumference of a circle?
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
