Pi is the most widely known mathematical constant that is commonly defined as the ratio of a circle’s circumference to its diameter approximately equal to 3.14159. It is also represented by the Greek letter “π”.
I am writing here about the Pi because It always attract me and in my programming life there are many situation when I need to use the pi value in programming such as to calculate the area of the circle. Pi is an irrational number, meaning its digits go on forever in a seemingly random sequence. Commonly we use the 22/7 to calculate the value of Pi that gives the never ended decimal represented without any repeating pattern.
Approximate value
Fractions: Approximate fractions include (in order of increasing accuracy) 22/7, 333/106, 355/113, 52163/16604, 103993/33102, and 245850922/78256779
Decimal: The first 100 decimal digits are 3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510 58209 74944 59230 78164 06286 20899 86280 34825 34211 70679 ….
Binary: 11.001001000011111101101010100010001000010110100011 ….
Hexadecimal: The base 16 approximation to 20 digits is 3.243F6A8885A308D31319 …
Use Pi in C#
In C#, Math.Pi field Represents the ratio of the circumference of a circle to its diameter, specified by the constant, π. And the value of this field is 3.14159265358979323846.
The following example uses PI to calculate the area of the circle.
class UseOfPi { static void Main(string[] args) { UseOfPi objClass = new UseOfPi(); double radius = 7.8; double AreaOfCircle = objClass.GetArea(radius); } public double GetArea(double radius) { double area = Math.PI * radius * radius; return area; } }
Use Pi in JavaScript
We can use math.pi to get the constant value of PI. Value of the PI is approximately 3.14159. You can use math.pi in JavaScript like this:
<html>
<head>
<title> Value of PI </title>
</head>
<body>
<script language="JavaScript">
var result = Math.PI;
document.write( "The Approximate value of PI is: " + result );
</script>
</body>
</html>See another example: How to calculate area of circle in JavaScript
Character Encoding
Character | ∏ | ∐ | ||||||||||
Unicode name | n-ary product | n-ary coproduct | mathematical bold | mathematical bold | mathematical italic | mathematical italic | ||||||
Encodings | decimal | hex | decimal | hex | decimal | hex | decimal | hex | decimal | hex | decimal | hex |
| Unicode | 8719 | U+220F | 8720 | U+2210 | 120503 | U+1D6B7 | 120529 | U+1D6D1 | 120561 | U+1D6F1 | 120587 | U+1D70B |
| UTF-8 | 226 136 143 | E2 88 8F | 226 136 144 | E2 88 90 | 240 157 154 183 | F0 9D 9A B7 | 240 157 155 145 | F0 9D 9B 91 | 240 157 155 177 | F0 9D 9B B1 | 240 157 156 139 | F0 9D 9C 8B |
| UTF-16 | 8719 | 220F | 8720 | 2210 | 55349 57015 | D835 DEB7 | 55349 57041 | D835 DED1 | 55349 57073 | D835 DEF1 | 55349 57099 | D835 DF0B |