If a circle has an area of 100 pi square units and a chord of 6 units what is the length of the intercepted arc?
arc length= angle*radius
= radius*2 arcsin(chord/2radius)
but if area=100PI, then radius must be 10
arclength=20 arcsin (6/20)=20*.305=6.1 units. http://mathworld.wolfram.com/CircularSegment.html