Inani elaziwa kakhulu ngokuba irrational ngu-pi. Le y-i-circumference (umgama ojikeleze) yesangqa yahlulwahlulwe nge-diameter yaso (umgama onqumla kwisangqa). Inani linye kuzo zonke izangqa. Inani eliyi-pi lingaphantse lithi 3.1415926535 ... .