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# pi

Given any circle, the ratio of the circumference to the diameter is an irrational number usually referred to as pi and denoted by the Greek letter $$\pi$$.

Figure 1: The Definition of Pi

This ratio is the same regardless of the size of the circle, and is approximately 3.1415926. Pi is an irrational number, so its decimal representation cannot be finitely represented. Pi is also known to be a transcendental number, which means that it is not the solution of any strictly algebraic equation.

Citation Info

• [MLA] “pi.” Platonic Realms Interactive Mathematics Encyclopedia. Platonic Realms, 11 Jul 2014. Web. 17 Feb 2019. <http://platonicrealms.com/>
• [APA] pi (11 Jul 2014). Retrieved 17 Feb 2019 from the Platonic Realms Interactive Mathematics Encyclopedia: http://platonicrealms.com/encyclopedia/pi/

Pi, the Definition!

How many times have you asked "what is Pi" only to hear the response, "3.14". Let this poster herald the truth: Pi is a ratio!