This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Arclength. Curve and polygonal paths The arclength is the smallest number that the lengths of such polygonal paths can never exceed Arclength svg This image was taken from the in english here org Arclength The author released it for public domain and granted permission to use it for any reason whatsoever en Michael Hardy Arc