# What is the stadium curve, and how differentiable is it?

What is the definition of a stadium curve and does it have a curvature that is defined and continuous at each of its points?

• Based on the responses below, it seems that the curvature is not defined at each point. There are four points where the curvature has a discontinuity, namely the points where the semicircles contact the straight sides. – S. Carnahan May 7 '10 at 5:52