1. The problem statement, all variables and given/known data Our prof talked about arc length as a parameter today and I understand how to do problems associated with it, however I do not fully understand why we do it. 2. Relevant equations In our text, the only relevant reading says: "A curve in the plane or in space can be parametrized in terms of the arc length s." Would someone be able to give me a geometric interpretation on why we need to do this parametrization? Thanks!