Answer:
since the number of degrees in a straight line is 180, we will subtract 140 from that to get 40 degrees for angle AOB. O being the midpoint of the circle. 40/360=1/9. So the length of AB would be 1/9 of the circumfrence of the whole circle. Circumfrence=13^2pi= about 530.9. 1/9 of this is 58.9 ,
