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Given that the circumference of any circle is 2 * pi * r, where pi is the mathematical constant (~3.14) and r is the radius, solving for the radius is quite simple.
we'll call the circumference c:
c = 2*pi*r
divide both sides by 2*pi:
c/(2pi) = r
and then the diameter is just 2 * radius.
Area = pi*(r)^2 = pi*(c/(2*pi))^2 = (c^2)/(4*pi)
(~ denotes approx. value)
Quick example:
So if a circle has a circumference of 30cm:
30 cm= 2 * pi * r
r = (30cm)/(2*pi)
r = (30cm)/(2*3.14) = ~4.78 cm
diameter = 2 * ~4.78 cm = ~9.56 cm
area = (30 cm)^2 / (4* ~3.14) = ~71.66 cm^2
c = 30 cm, r = ~4.78 cm, d = ~9.56 cm
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How do you find the diameter and then the circumference if you have the radius?
Diameter = radius * 2 Circumference = pi * diameter.
How do you find the circumference from the area?
Well, you find the area of a circle by multiplying (pi times radius2) or (pi times radius times radius). The radius is half of the diameter. The formula for the circumference is (pi times diameter). Multiply the radius times 2 to get the diameter. Multiply the diameter times pi.
How can you find the diameter and the radius if the circumference is given?
Diameter = circumference/pi Radius = circumference/2*pi
Find the circumference and the area of a circle with radius?
Circumference = pi (3.14) times the diameter (radius times two) Area = pi (3.14) times the radius squared
What number is in the circle to find radius and diameter?
There are four common measurements of a circle, radius, diameter, circumference, and area. Here is how they are related. Diameter is how far across it is at the widest point. Radius is 1/2 of diameter. Diameter X pi = circumference. pi = 3.1416 Area = pir2
How do you find a diameter of a circle?
If you have the circumference: circumference = (pi) * diameter diameter = circumference / (pi) If you have the area: area = (pi) * radius * radius radius = square_root(area / pi) radius = diameter / 2 diameter = 2 * square_root(area / pi)
How do you find the diameter and then the circumference if you have the radius?
Diameter = radius * 2 Circumference = pi * diameter.
How do you find the circumference from the area?
Well, you find the area of a circle by multiplying (pi times radius2) or (pi times radius times radius). The radius is half of the diameter. The formula for the circumference is (pi times diameter). Multiply the radius times 2 to get the diameter. Multiply the diameter times pi.
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
How do you find the perimeter and area of a circle?
perimeter (circumference): diameter times pi (3.14) area: radius times radius times pi (3.14) Area = pi*radius squared Circumference = 2*pi*radius or pi*diameter
How can you find the diameter and the radius if the circumference is given?
Diameter = circumference/pi Radius = circumference/2*pi
How do you find the circumference if you know the radius?
Okay finding circumference from knowing the radius right? The radius is equal to half the diameter and circumference is equal to pi * diameter. So double the radius and multiply it by 3.14 then you will get the circumference!
What is the circumference and area of a circle that has a radius of 4?
To find the circumference of a circle then multiply pi (3.14159265...) by the diameter of the circle. To find the area then multiply pi by the radius squared.
Find the circumference and the area of a circle with radius?
Circumference = pi (3.14) times the diameter (radius times two) Area = pi (3.14) times the radius squared
find the length of the radius the circumference and the area of the circle the center is 20 feet use 3.14 for pi?
radius = diameter/2 circumference = 2*pi*radius or pi*diameter area = pi*radius2
How do you find the circumference with no radius or diameter?
They would have to give you enough information to eventually get the diameter. If they gave you the area of a circle and asked for the circumference, you can determine the radius, and from the radius the diameter, and then the circumference. If they said "What is the circumference if the area of a circle is 36pi?" Area of a circle is pi*r2, which would give us a value for r = 6 Diameter is 2*r, or = 12. Circumference is d*pi, or 12pi
