That's a nice little algebra exercise.
Before you can begin, you need to know the formulas for the
circumference and area of a circle:
-- Circumference = (pi) x (diameter)
-- Area = (pi) x (radius)2
-- It will also be very helpful to know that the radius is 1/2 of the diameter.
And now you're ready to begin. What I'll do is solve the area formula for the radius,
adjust that to equal the diameter, and substitute that into the circumference formula.
Fasten your seat belt if necessary.
Area = (pi) x (radius)2
Divide each side by (pi):
(radius)2 = area/pi
Take the square root of each side:
Radius = sqrt (area/pi)
Double each side:
2 x radius = 2 sqrt(area/pi)
Now go and get the formula for the circumference:
Circumference = (pi) x (diameter)
Do you have the diameter ? Look a few lines higher ... you just found (2 x radius),
and that's the diameter. Substitute it in the circumference formula:
Circumference = (pi) x 2 x sqrt(area/pi) .
That's it. If you know the area, then you know everything on the right side,
and you can calculate the circumference.
The result can be tidied up a bit, without changing it:
Circumference = 2 x sqrt( area x pi )
Area of a circle = 3.14 * r2 Thus, radius, r = root of ( Area of a circle / 3.14 ) --------- equation 1 Circumference of circle = 2 * 3.14 * r Therefore, from (equation 1), Circumference = 2 * 3.14 * root of ( Area of a circle / 3.14 ). In a nutshell, first find the radius and then the circumference.
What do you have? The area of the circle or the circumference? Area: divide the area by pi, then square root it Circumference: divide the circumference by 2 then divide it by pi
Divide its circumference by 2*pi which will give the radius of the circle. Area of the circle then is pi*radius squared
Area of a circle is: A=π*r2 and r=circumference/2. Find 1/2 of the circumference and square it (multiply by same number), then multiply by pi.
Square root (Area/pi) to get the radius Then 2xRadiusxPi= Circumference
The circumference is: 32.1
The area of a circle when the circumference is 10 inches is: 7.96 square inches.
3020.68cm2
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.
Circumference of a circle = 2*pi*radius or diameter*pi Area of a circle = pi*radius squared
Area of a circle = 3.14 * r2 Thus, radius, r = root of ( Area of a circle / 3.14 ) --------- equation 1 Circumference of circle = 2 * 3.14 * r Therefore, from (equation 1), Circumference = 2 * 3.14 * root of ( Area of a circle / 3.14 ). In a nutshell, first find the radius and then the circumference.
Area of the circle = (circumference)2 / (4 pi)Area = 0.0796 circumference2(rounded)
What do you have? The area of the circle or the circumference? Area: divide the area by pi, then square root it Circumference: divide the circumference by 2 then divide it by pi
Divide its circumference by 2*pi which will give the radius of the circle. Area of the circle then is pi*radius squared
Area of a circle is: A=π*r2 and r=circumference/2. Find 1/2 of the circumference and square it (multiply by same number), then multiply by pi.
Square root (Area/pi) to get the radius Then 2xRadiusxPi= Circumference
If the object is a circle and if 9.5 is the diameter, the area is 70.88 and the circumference is 29.85