The circumference of a triangle is given by 2*pi*r where r is the radius and the area is pi*r^2.
Here circumference = 12*pi = 2*pi*r
=> r = 6
The area = pi*r^2 = 36*pi
The area of the circle is 36*pi
Given the area of a circle is 12pi.
Then we will calculate the radius using the circumference formula.
==> C = 2* pi *r = 12 pi
==> r = 12pi/2pi = 6
Now we will calculate the area of the circle.
==> We know that A= r^2 * pi
==> A = 6^2 * pi = 36 pi = 113.1 ( approx)
Then the area of the circle whose circumference 12pi = 36pi = 113.1 square units.