I thought of an `L` suffix too, but I feel like if we are going to do that we should do it everywhere, which is definitely overkill.  Yes, I know that mathematically a straight line is a curve, I think my real problem with it is just consistency.  Having the lens for `ArcLength` called `curveLength` is just strange, no one would ever remember it.

Perhaps we should just stick with `getArcLength`.