Double the radius
You times the radius by 2.
Divide the diameter by 2.
The radius of a circle is half of the diameter! So, if the diameter was four inches, the radius would be two inches!
Diameter of a circle = 2*radius Circumference of a circle = 2*radius*pi
The longest chord in a circle is its diameter and halve of this is its radius.
you cant: pi is the same for any circle - 3.1415... the diamter or the radius has to be given diameter divided by two equals the radius the radius times two equals the diameter
Area of a circle = pi*radius2 Radius = diameter/2
circumference of a circle = 2*pi*radius or pi*diameter
the radius is half the diameter
Radius is one-half of the diameter of a circle. Therefore, the radius of an eight-inch diameter circle is four inches. The diameter of a circle is a straight line joining a point on the circumference through the centre to the 'opposite' point on the circumference.
If you mean the diameter and radius of a circle given the circumference it is:- diameter = circumference/pi radius = circumference/(2*pi)