Delphi Basics : Pi command

DelphiBasics

Pi
Function

The mathematical constant

System unit

function Pi():Extended;

Description

The Pi function returns a floating point value giving a useful approximation of the value of Pi.

The circumference of a circle Pi * Diameter.

Related commands

Cos		The Cosine of a number
Extended		The floating point type with the highest capacity and precision
Sin		The Sine of a number
Tan		The Tangent of a number

Download this web site as a Windows program.

Example code : Get the area and circumference of a circle

var
  myPi : Extended;
  diam : Integer;
begin
  diam := 10;

  // Show circumference and the area of a circle
  // with diameter - 10 cm
  ShowMessage('     Diameter = '+IntToStr(diam));
  ShowMessage('Circumference = '+FloatToStr(Pi*diam));
  ShowMessage('         Area = '+FloatToStr(Pi*(diam/2)*(diam/2)));
end;

Show full unit code

   Diameter = 10
  Circumference = 31.4159265358979
   Area = 78.5398163397448