When you measure the length of a straight surface, you use a ruler or a tape measurer. These tools aren't as useful when you need to measure the length of a curve; instead, you need a curvimeter, which is even more exact than a compass. To learn about this invention and build a model you'll be proud to display, purchase the UGears STEM LAB Curvimeter. This item looks like a clock, except that its face displays distances in centimeters, inches, meters, and feet rather than times.
Part Number: UTG0073