The number Pi (π) is a number that represents the result of division between the perimeter and the diameter of a circle.
It is an infinite numerical proportion, meaning its sequence of numbers is endless. Because of this, PI is classified as an irrational number.
What is the value of Pi?
The value of Pi is 3,1415926535897932384626...
Representation of the value of Pi.
How is it calculated?
The value of Pi represents the calculation of the division between the value of the perimeter and the diameter of a circle, that is, π = perimeter/diameter.
The perimeter of a circle is the measure of its back (length). The diameter is the measurement value from one end of the circle to the other. If we divide the perimeter by the diameter, the result is equal to Pi.
See the image below:
What is the value of Pi for?
The Pi number is used in geometry calculations, primarily to find out what the lateral area of a cylinder is. For this, the following formula is used: Al = 2 π * r * h.
In the formula:
Al = lateral area value.
π = Pi.
r = radius size.
h = height measurement.
See this example with a cylinder that has a radius of 8 cm.
In the example above, the side area of the cylinder is 40.67 cm.
Pi number history
It is not known for sure the origin of the discovery of Pi, but there are historical records that indicate that in Egypt and Babylon there were already studies similar to the number.
Who arrived at the calculation of the value of Pi was the mathematician Archimedes, who lived in Greece between 287 a. C and 212 a. Ç. He got the value by continuing the studies on circumference that Euclid of Alexandria, another Greek mathematician, had already started some years earlier.
As studied today, the insertion of IP in mathematics is credited to the mathematician William Jones, who used it in the early 18th century.
Pi symbol
The Pi symbol (π) is represented by the Greek letter that has the same name. Probably the symbol was chosen because, in Greek, it means a "thing that cannot be materialized or performed".
The meaning of Pi in Greek is related to the idea of an infinite number, in which its ending cannot be found.
The symbol chosen to represent the number is the first letter of the word perimeter in Greek: περίμετρος.
Also read the meaning of number and know what a Prime number.
