The circumference is 24[tex] \pi [/tex] or about 75.4, because the equation for circumference of a circle is diameter x pi.
the area is 144[tex] \pi [/tex] or about 452.4, because the equation for solving area of a circle is pi x (radius squared). the radius is half the diameter, which is 12. 12 squared is 144, and 144 times pi is about 452.4. :)