# Circle diameter = 8

of a circle is
I want to calculate
 Area Circumference Radius Diameter All

A circle has diameter = 8
Calculate Area, Circumference, Radius, Diameter

A = πr2

## Rearranging the equation, we get:

 r2  = A π

 r  = √A √π

 r  = √8 √3.1415926535898

 r  = 2.82843 1.77245

r = 1.5957691216057

## Calculate circumference (C):

C = 2πr
C = 2π * 1.5957691216057
C = 3.1915π or 10.0265

## Calculate diameter (d):

d = 2r
d = 2 * 1.5957691216057
d = 3.1915382432115

### What is the Answer?

r = 1.5957691216057
C = 3.1915π or 10.0265
d = 3.1915382432115

### How does the Circles Calculator work?

Free Circles Calculator - Calculates and solves for Radius, Diameter, Circumference, and Area of a Circle.
This calculator has 1 input.

### What 3 formulas are used for the Circles Calculator?

d=2r
A = 2πr2
C=2πr

For more math formulas, check out our Formula Dossier

### What 7 concepts are covered in the Circles Calculator?

area
Number of square units covering the shape
circle
the set of all points in the plane that are a fixed distance from a fixed point
circles
circumference
the perimeter of a circle or ellips
diameter
distance from two endpoints of a circle through the center
d = 2r
origin
On a two digit coordinate plane, the point (0, 0), where the x-axis and y-axis cross.