All circle calculations use the constant π (pi). The circumference close circumferenceThe distance around a circle; its perimeter. divided by the diameter close diameterThe distance across the ...

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 about Pi and how it is represented in the national ...

Approximating Pi By Rick Groleau Posted 09.01.03 NOVA Around 250 B.C., the Greek mathematician Archimedes calculated the ratio of a circle's circumference to its diameter. A precise determination ...

How to Solve for Radius in Excel. 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.

The vertical side of this rectangle is the radius of the circle and the length of the side is half of the circumference (so, 2π R). Yes, the area of this rectangle would be π R2.

Actually, the ratio came from nature—it’s the ratio between the circumference of a circle and its diameter, and it was always there, just waiting to be discovered. But who discovered it?

Time is a flat circle, Matthew McConaughey tells us, neglecting to explain how then we could measure time's circumference to derive its diameter, using pi.