The triangle has a 60° angle, and the two adjacent sides are 12 and "12 times the square root of 3".
So, the area of the triangle, Δ = sq. units.
Now, we have to find the radius of the circle with the same vertex as a center, if the arc in the triangle bisects the area of the triangle.
So, if the radius of the circle is r units, then
⇒ 0.5238 r² = 54
⇒ r² = 103.092
⇒ r = 10.15 units. (Answer)