In the figure below is represented the center circle O. Pubctele A and B belong to the center circle O, so that the measure of the arc AB is equal to 120° and the distance from the center of the circle to the chord AB is 2 cm. The length of the circle is equal to:
a) 8 pi cm
b) 4 pi cm
c) 16 pi cm
d) 64 pi cm
