Answer:
actually, this is the case of circumcircle of equilateral triangle
so, Raidus = 2/3 of midean or height.
so, height of triangle will be = 12 cm
and side of that triangle will be h = root 3 /2 * a
so, side, a = 24/root 3
area = root 3 / 4 * a^2
= root 3/4 * 24*24 /3
=144/root 3 = 83.1408 cm^2