Area of equilateral triangle S=[a^2*3^1/2]/4 so a=6
a- side of triangle. R- raduis of circumscribed circle.
R=a/(3^1/2) so R=2*3^1/2 and Pi*R^2=12*Pi.
That is right.
Radius of circumcircle = a/sqrt(3); a = side of triangle
Radius of incircle = [sqrt(3)*a]/6; a = side of triangle
These formulas are valid for equilateral triangles only!