Since the "cone" bit only comes into play for the volume and surface area you don't have to worry about that part. That means you can treat is as a plain circle. So c=pi*2r. So, divide by 2 pi.
Circumference=2*pi*radius
radius = circumference/2*pi
You can either measure it, or calculate it if you know the diameter (radius = diameter / 2), or the circumference (radius = circumference / (2pi)).
Well, if you know the diameter you divide that by two to get the radius.
Divide the circumference by 2*pi will give the radius of the circle.
Circumference=2*pi*radius
Circumference of a circle = 2*pi*radius
If you know the circumference of a circle, you can find the radius by dividing the circumference by the value of Pi (3.14159...)
Radius (not raduis) =circumference/(2*pi)
radius = circumference/(2*pi)
radius = circumference/2*pi
You can either measure it, or calculate it if you know the diameter (radius = diameter / 2), or the circumference (radius = circumference / (2pi)).
Volume of a cone = (1/3)*(area of base)*(height). Area of a circle = pi*radius². But you know circumference. Circumference = 2*pi*radius. Rearrange: radius = C/2/pi. Substitute this in for radius above: Area = pi*(C/2/pi)² = C²/(4*pi). Volume = C²*h/(12*pi) [C is circumference, h is height]
The equation for circumference is C=2(pi)(r) where C is the circumference and r is the radius. You can find the radius by plugging in the circumference into this equation and solving the equation.
Well, if you know the diameter you divide that by two to get the radius.
The circumference of a circle that has a radius of 5 inches is 10 X pi or approximatly 31.415926535897932384626433832795. If you know the radius you can find the circumference by multiplying it by 2(pi)
Where C=circumference, r= radius and d=diameter To find circumference: C=2 x pi x r or you can use the formula C=pi x d To find diameter just multiply the radius by 2 if you know what the radius is. If you do not know the radius, but you know the circumference and need diameter use the following formula: C/pi=d Happy Computing!!!