Puzzle

The wrap-around distance is a bit longer than the end-to-end distance. Here's why:

The balls "just fit" in the tube, and let's assume that the walls and ends of the container are very thin, so for purposes of calculations we can ignore their thickness.

The length of the container is three times the diameter of a tennis ball. The distance around the container is the distance around one of the balls at its fattest point. This is equal to pi times the diameter of a ball.

Pi is equal to 3.1416. Since this is more than 3, the distance around the container is more than the end-to-end distance.

Pi is a special number that is defined as the ratio of the circumference of a circle to its diameter. This is true of all circles. Calculations of pi have become more accurate over the years. Thousands of years ago it was thought to be 3.

3.1416 is actually an approximation. Pi is a non-repeating decimal number that will go on forever. If you calculate it to ten digits, it is equal to 3.141592653.

Here are other Web sites with information about pi:

www-gap.dcs.st-and.ac.uk/~history/HistTopics/Pi_through_the_ages.html