## Our name

Our name, “πi”, consists of 2 mathematical symbols, used widely in maths and science. The symbol “$$\pi$$” and the symbol “i”.

$$\pi$$, is a mathematical constant defined as the ratio of a circle’s circumference to its diameter. Taking any circle, regardless of its size,

$$\pi = \frac{C}{d}$$ where C is the circumference of the circle and d its diameter.

π is an irrational number, i.e. a number that cannot be expressed as a simple fraction. This means that π has an infinite number of digits, the first few of which are π=3.141592653589793238462643383279502884197...  .

Nobody knows how π was discovered, but we do know that π has been known for over 4000 years, used in 2000 BC by the Babylonians.

This number is celebrated on Pi Day, March 14, since March is the 3rd month of the year, and 3.14 are the three most significant digits of the number π. Albert Einstein was also born on 14 March 1879.

The symbol i, is an imaginary number, which is defined as i=√(-1), hence  i2=-1. Even though it is known that you cannot take the square root of a negative number and hence the number i may not make sense, imaginary numbers are very useful and are being widely used in science and engineering.