"arc-length" is referenced in the pages listed below.
Definition of arc length and formula to calculate it from the radius and central angle of the arc.
We can approximate the length of a curve by using straight line segments and can use the distance formula to find the length of each segment. Then, as the segment size shrinks to zero, we can use a definite integral to find the length of the arc of the curve. Interactive calculus applet.
(C) 2011 Copyright Math Open Reference. All rights reserved