Two equilateral triangles of side 12 cm, sharing the same centre with one…

Two equilateral triangles of side 12 cm, sharing the same centre with one triangle inverted relative to the other, are placed one on top of the other so that a 6-pointed star (hexagram) is formed. The star's six outer vertices lie on a circle. What is the area of the circle not enclosed by the star? (Give the answer to the nearest sq cm.)