radius = circumference/(2*pi)
If you have the radius, then area = pi*r2 which you then round to the nearest hundredth. If you do not know the radius but do know the diameter or circumference, you can calculate the radius. Otherwise you need to measure it.
If you want an approximate answer, you can measure it with string. If you want an exact answer and know the radius, multiply by 2*pi to find the circumference.
Given the circumference, divide the circumference by pi (3.1416) to give the diameter of the circle, then divide by 2 to find the radius (half of the diameter).Since C = (pi) D and D = 2r, then r = C/2piSee related links for more help with circles.
well,first the radius is half of the chord. Radius is the distance from the circle centre to the chord end. The chord is the line joining the ends of the arc. Draw this line. Call the distance from the arc of the circle at its deepest point to the mid point of the chord "c". If extended, this line will go throught the centre of the circle. Call half the length of the chord "y". Then the properties of circles and chords is that c(d-c)=y2 where d is the circle diameter, so that d = y2/c + c. And then radius is half that.
If by "it" you mean a circle, once you know the diameter, you can calculate its radius, its circumference, and its area.
If you do not have the area, what do you have? The radius is half the diamiter The radius is PieR2 Worked backwards if you know the circumfrence.
Pi x the diameter of the circle will hive you the circumference. The diameter is double the radius so the answer to your question is pi2r.
The circumference (c) of a circle = 2πr (where r = radius). Therefore if you know the circumference, the radius (r) = c/2π.
If you know the diameter of the circle, multiply that by Pi (about 3.1416). The result is the circumference.
Wow, a question I actually know! The radius of a circle is 1/2 of the circumfrence. In other words, if your body was a circle, and you spread out youre arms, the area from you're heart to the tip of you're fingers would be the radius.
You already know the radius.
Since the formula for the area of a circle is pi times the radius squared and the formula for the circumference is two times pi times the radius, you would find the circumference by first dividing by pi. This would give you the radius squared. Find the square root of this value. This will give you the length of the radius. Take this length and multiply it by two times pi.
It depends on the values you have. The base of a cylinder is a circle. If you know the circle's diameter, half it to find the radius. If you know the circle's circumference, divide by 2pi to find the radius. If you know the circle's area, divide by pi and take the square root to find the radius.
Diameter = 2*Radius
radius = circumference/2*pi
Area of Circle = pi (radius)2 So , using this formula we can find the radius and also the diameter. Diameter = 2(radius)