This may be a specific number of decimal places or significant figures. The circumference of a circle is the distance around the shape. The circumference is the perimeter of the circle.

Around 250 B.C., the Greek mathematician Archimedes calculated the ratio of a circle's circumference to its diameter. A precise determination of pi, as we know this ratio today, had long been of ...

Pi (Greek letter π) is the symbol used in mathematics to represent a constant — the ratio of the circumference of a circle to its diameter — which is approximately 3.14159. Pi has been ...