You use the information that you do have, and a formula that relates it to the
radius or diameter of the circle. As an example: The circumference is very helpful
if you know it.
diameter = 2 * radius
Double the Radius to Calculate the Diameter.
to calculate circumference you find a circles radius or diameter. you do diameter times pi or radius times 2 times pi. the you have circumference!
You can either measure it, or calculate it if you know the diameter (radius = diameter / 2), or the circumference (radius = circumference / (2pi)).
If you know the circumference, the ration of the diameter to the circumference is π, so diameter = circumference/π If you have the radius, diameter = 2 x radius
diameter = 2 * radius
Double the Radius to Calculate the Diameter.
Radius of a circle = diameter/2
Radius of a circle = diameter/2
to calculate circumference you find a circles radius or diameter. you do diameter times pi or radius times 2 times pi. the you have circumference!
You can either measure it, or calculate it if you know the diameter (radius = diameter / 2), or the circumference (radius = circumference / (2pi)).
If you know the circumference, the ration of the diameter to the circumference is π, so diameter = circumference/π If you have the radius, diameter = 2 x radius
Circumference = diameter*pi
Divide the diameter by 2.
Of a circle: divide the length of the circumference by the value of Pi (about 3.14159). The answer is the diameter. Half of the diameter is the radius
The radius is one -half of the diameter. It is the distance from the circle center to any point on the circumference.
To calculate the radius of a quarter in millimeters, you first need to know the diameter of the quarter. A U.S. quarter has a diameter of 24.26 mm. The radius is half of the diameter, so you divide 24.26 mm by 2, resulting in a radius of approximately 12.13 mm.