Today we'll look at measurement and curves. You'll learn how to measure wiggly shapes whether convex or concave. Here's how: Whether it's an inside or outside radius, or a combination of both, measuring a curved surface or edge can be tricky. While metal tape measures are flexible, they don't hug a curve tightly enough to provide an accurate measurement. And while a string or cloth tape works all right on some outside curves, it can be hard to keep in place. It also provides -- at best -- questionable accuracy. Next time you want to measure a curved surface, use masking tape; it goes with the flow and stays in place. And that's the On The House tip for today.