By doubling the number of sides of the hexagon to a 12-sided ... The diameter of the circle is given an arbitrary value of 1; it doesn't matter if that number represents an inch, a foot, or ...

and you can see that the ribbon is just over 3 times the diameter of 1 circle. This number, called π (or pi), is approximately 3.14. You have shown that the circumference of a circle is π × ...

The radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference. Likewise, a sphere's volume is ...

Actually, the ratio came from nature—it’s the ratio between the circumference of a circle and its diameter ... (One cubit is about 18 inches, though it was measured by a person’s forearm ...

But I found dignity in the Greek form of my name. I am Pi, the ratio of the circumference of a circle to its diameter. Picking up the phone here at the Smithsonian, I set out to find out more ...

Around 250 B.C., the Greek mathematician Archimedes calculated the ratio of a circle's circumference to its diameter ... of sides of the hexagon to a 12-sided polygon, then a 24-sided polygon ...