Circumference pi, is represented by the Greek letter . The first few decimal digits of the numerical value of are 3.141592653589793 ... Pi is defined as the ratio of a circle's circumference to its diameter : Or, equivalently, as the ratio of the circumference to twice the radius. The above formula can be rearranged to solve for the circumference: The use of the mathematical constant is ubiquitous in mathematics, engineering, and science. In "Measurement of a Circle" written circa 250 BCE, Archimedes showed that this ratio (, since he did not use the name ) was greater than 3 but less
Circle line party Circle line party A Circle line party is a type of subway party occasionally held on the Circle line of the London Underground. Although the time and place of these parties is planned, the event itself occurs spontaneously, as each participant decides for themselves what sort of revelry, costume, decorations, snacks, libations and guests to bring to the party. The participants decorate the carriages festively, and play music, either live or on portable sound systems, disguised to appear as normal luggage. Other activities include setting up pole-dancing poles on the trains. Free drinks, snacks and sweets are provided, often being