because cicle sounds weird. r is used as an abbreviation for radius meaning half the diameter of the circle.
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∙ 15y agoThe director circle of a circle with radius r is a concentric circle with radius r*sqrt(2).
Circumference of a circle with radius 'r' = 2(PI)(r) ~ 6.28(r)
The radius of a circle is half the diameter so if the radius of a circle is r, then the diameter is 2r.
An annulus. Area = pi (R2 - r2) when R is radius of larger circle and r is radius of smaller circle.
The area of a circle with radius r is pi*r*r and its circumference is 2*pi*r Use the first to find r and then use that value of r in the second to find the circumference.
The area of the circle becomes 9 times the area of the original circle. Original circle = Pi * (r ^ 2) = Pi * r * r New Circle = Pi * ((3 * r) ^ 2) = Pi * 9 * r * r
The director circle of a circle with radius r is a concentric circle with radius r*sqrt(2).
Circumference of a circle with radius 'r' = 2(PI)(r) ~ 6.28(r)
The radius of a circle is half the diameter so if the radius of a circle is r, then the diameter is 2r.
I don't think there is one. There is pi*r*2 (* meaning times by), which is the area of a circle. Other wise I'm not sure.
R = Radius The radius is half the diameter of a circle.
Area of a circle is calculated by A=2*p*r where A represents the circle's area and r is the radius of the circle.
R = radius of big circle, r = radius of little circle Area of circle = pi x R x R = 4 x pi x r x r = 4 x pi x 3 x 3 Therefore R x R = 36 and so R = 6 inches
Area of a circle = pi R2 'R' is the length of the radius of the circle. That's the distance from the center of the circle to any point on the circle.
Area of a circle= (22/7)*r^2 where, r is the radius of the circle when r=15, area of the circle= 3.14*15*15 = 706.5 sq.units
r = d * 0.5, r = C / (2 * 3.14), r = √(A / 3.14) The radius of a circle when the diameter is known: d = 2 * r d is the diameter of the circle r is the radius of the circle r = d / 2 = d * 0.5 The radius of a circle when the circumference is known: C=2πr C is the circumference of the circle π is a constant approximately equal to 3.14 r = C / (2 * π) = C / (2 * 3.14) The radius of a circle when the area is known: A=π(r)^2 A is the area of the circle r = √(A / π) = √(A / 3.14)
If 'R' is the radius of the circle, then-- area of the circle is [ pi R2]-- perimeter of the circle is [ 2 pi R ]