How To Figure A Diameter From A Circumference?

The formula for finding out the circumference of a circle is:
Circumference = 2(pi x r)
Where r is the radius.
Now, the value of pi is always taken as 3.14. If we have the value of the circumference, we can find the value of the radius.
Let's suppose that the circumference is x. Therefore, to find the radius:

C = 2(Pi.r)
x = 2(3.14.r)
x = 6.28 (2r)
x = 12.56r
r = x/12.56

Now the diameter is always twice the length of the radius. Therefore, any answer that you get for the radius, you just have to multiply it by 2 to obtain the value for the diameter.
In this case:
Diameter = 2xr
Diameter = 2(x/12.56)

Let's do this with an actual number. Supposing the circumference is 20cm, the radius would be:
20 = 2 (Pi.r)
20 = 2 (3.14r)
20 = 6.28r
r = 20/6.28
r = 3.19 cm

Diameter = 2r
Diameter = 3.19 x 2
= 6.38 cm
thanked the writer.
Diameter x  Pi = circumference

diameter = circumference / pi

Pi = 3.141592654

7 1/2 / 3.141592654 =

thanked the writer.
I have a circumference measurement of 28 1/2 inches and I need to know the diameter of same
thanked the writer.
The circumference of a mirror is 185 cm
find the diameter of the mirror
thanked the writer.
Diameter = Circumference/Pi

pi = 3.14 or 22/7

Circumference 1:  c1= 7 1/2 = 15/2

Circumference 2: C2= 14 1/2 = 29/2

D1=c1/pi

= (15/2) / (22/7)
= 15/2 x 7/22
=105/44
= 2.386 inches

D2 = c2/pi
= (29/2) / (22/7)
= 29/2 x 7/22
= 203/ 44
= 4.614 inches.
thanked the writer.
The circumference of a circle is;

Circumference= 2*pi*r

Pi= constant= 3.14

If we are given circumference of the circle, then the radius of the circle can be calculated by the formula;

radius = circumference/ 2*pi

The radius of a circle is equal to the half of diameter of the circle.

Radius = Diameter/ 2 