How Many Diameters?

Interact with this app for a minute or two. As you do, carefully observe what happens. Then answer the questions that follow.

How many diameters wrap perfectly around a circle?

Between 2 and 3 Between 1 and 2 Between 3 and 4 Between 4 and 5

Is there a familiar number in the range you selected (in your answer to the previous question) that relates to circles? If so, what is it? How would you describe or define it?

Suppose a circular above-the-ground swimming pool has a diameter of 10 feet. Estimate (or calculate) its circumference.

Information: How Many Diameters?