Radius (not raduis) =circumference/(2*pi)
A radius (not raduis) of 15 units implies a circumference of 94 units.
Circumference = 2*pi*radius (not raduis) = 19 cm, approx.
The radius (not raduis!) is 3.183 cm, approx.
The circumference of a circle, if the radius is 11cm, is about 69.12cm
Radius = circumference/pi
If the radius (not raduis) is 25 feet then the diameter is 50 feet.
C = about 12.57
Divide the circumference by 2pi
The circumference is 2*pi*radius (not raduis) and this formula is applicable whether the radius is an integer, a fraction, or even an irrational number.
circumference = 2*pi*9 inches
A circle with a radius of 8 units has a circumference of 50.3 units.