# Manuals/calci/PI

PI()

## Description

• This function gives the value of .
• The is a mathematical constant with a value approximate to 3.14159.
• It is denoted by the Greek letter .
• is commonly defined as the ratio of a circle's circumference to its diameter .
• So , the ratio is constant, and it is not considering the circle's size.
• is a transcendental number and irrational number.
• Being an irrational number, cannot be expressed exactly as a ratio of any two integers .
• But we can express as the fraction is approximate to the value , also no fraction can be its exact value.

## Examples

1. =PI() = 3.141592653589793
2. =PI()/4 = 0.785398163
3. =PI()/180 = 0.017453293
4. =PI()/(22/7) = 0.999597663
5. =PI()*(5^2) = 78.53981634(Area of circle with r=5)
6. =2*PI()*5 = 31.41592654(Circumference of a circle with r=5).

PI