The circumference of a circle is the distance around the shape. The ability to round a number to a number of decimal places or to a number of significant figures means that answers can be written to ...

Pi, a mathematical constant denoted by the Greek letter π, is the ratio of a circle's circumference C to its diameter d: π = C/d. The circumference of a circle is, in turn, equal to 2πr, where r is ...

Swiss researchers said on Monday they had calculated the mathematical constant pi to a new world-record level of exactitude. The constant π is represented in this mosaic outside the Mathematics ...