how to find the area of a circle 12cm?

The area of a circle where something is 12 cm:

R=12 cm  A=pi r^2=452.389cm^2

C=12 cm  A =  pi r^2=11.459 cm^2

D=12cm   A=113.097 cm^2

if 12 is the circumference

A = (12/PI)^2*PI/4 = 36/PI cm^2

if 12 is the diameter 

A' = PI/4*d^2 = 36PI cm^2

if 12 is the radius 

A'' = 12^2*PI = 144PI cm^2

A''/A' = 4 

A'/A = PI^2

A''/A = 4PI^2

What does '12 cm' represent??  Is it the radius, diameter or circumference?  Please clarify> 

Area = πr²,Circumference = 2πr, diameter = 2 × radius

So 12cm could be radius, diameter, or circumference.

MY best guess is Diameter, if so, radius = 6cm:

A = πr² = π(6²) = 36π or about 113 cm²

The 12 cm doesn't make sense.. Is 12 cm a diameter of a circle, a radius, or a circumference? 

Area of a circle = pi*radius squared

If C = 12 cm:

pi r = 6 cm

A = pi r^2 = 6 (6/pi) = 11.46 cm^2

The formula for the area of a circle is:

A = πr²

But you haven't specified what part of the circle measures 12cm.

Let's assume it is the *diameter*. If so, the radius is half that or 6cm.

Now plug in r = 6:

A = π * 6²

A = 36π cm²

That's the exact answer. If you want an approximate value, plug in your desired rational approximation of π (e.g. 3.14, or 3.14159, etc.)

A ≈ 113.1 cm²

A = Pi r^2                                         .

12cm is the circle's diameter?  Radius?  Circumference?  I'll assume diameter.

So cut the diameter in half to make it a radius.  Then it's (pi)r^2  (I don't have a pi symbol on my keyboard)  Pi times the radius squared.