Radius of a circle is half the diameter.
For any given circle draw a straight line from one point on the circulference, through the circle centre, to the opposite point on the circu,afenrece.
Then taking a rule measure the straight line distance. That is the diameter(d)
Half of this distance, that from the circle dentre to the circumference is the radius(r).
r + r = d
or
2r = d
or
r = d/2
From this straight line we can calculate both the area (A)and the circuference(C) by using the following eq'ns/
C = 2pir = pi*d
A = pi *r^(2)
'pi' is a constant for all circles. and the number 3.14 or 3.1416 or 22/7 are used in these APPROXIMATIONS.
Radius of a circle = diameter/2
We can calculate the area of a circle by using the formula areacircle pi times r2. We know that pi is about 3.14 and r is the radius of the circle. Πr2 Where: Π pi (3.14159265...) r radius of circle
a=3.14xradius squared
The perimeter or circumference of a circle = 2*pi*radius or pi*diameter
The area of a circle is: pi times radius squared
Radius of a circle = diameter/2
int radius = 2; int output; radius = radius * 2; output = radius * Math.PI; Console.WriteLine(output);
Double the Radius to Calculate the Diameter.
Radius of a circle = diameter/2
From what? You need other variables you can use in the standard circle formulae from which to calculate the radius.
Divide the diameter by 2.
pi radius squared
The radius is one -half of the diameter. It is the distance from the circle center to any point on the circumference.
you calculate the Area of the circle at the end of the Cylinder and then multiply it by the lenght to the second circle at the end of the cylinder Circle area= Radius*Radius* pi pi being 3.14159265
Not sure about crircumference, but radius = circumference/(2*pi)
the area of the circle is Pi X Radius squared
Circumference of a circle = 2*pi*radius or pi*diameter