# The Ultimate Guide to Understanding Pi: History, Calculation, and Fun Facts

Last updated on by ​Arikaran Kumar The mention of quintessential American Apple pie sounds and tastes delicious. So, you must be wondering why March 14th is celebrated as “Pie” day. On this day, do I get a free pie? Math geeks must be wondering what is the connection between the apple pie and the mathematical constant “π”? In this blog, let us explore this aspect of an important mathematical puzzle.

## What is Pi (π) as used by mathematicians?

Trust me there is a similarity between the quintessential apple pie and the mathematical constant “π”. Both are constants. Apple pie is a constant in most American parties, and the “π” is a mathematical constant. American parties will be incomplete without an apple pie, and so mathematics will be incomplete without the constant π. So, what the π stands for? It represents the ratio of the circumference of a circle and its diameter. Mathematicians have amply demonstrated this ratio to be approximately 3.14159. Expressed in fractions, π = 22/7.

Fun Fact !

π is an irrational number, no doubt it drives us crazy!

## Why is March 14th observed as Pi Day?

π Day is celebrated every year on , because the numerical date (3.14) represents the first three digits of the mathematical constant π. It also happens to be Albert Einstein’s birthday.

Celebrate Einstein’s birthday with a slice of a pie; you don’t have to choose between apple pie and π. People can say you cannot have your cake and eat it too. But this is a perfect example, where you can have your Pi (π) and eat it too. If you are celebrating solo, don’t skimp on it, you can eat the whole pie and enjoy!

## What are the applications of Pi (π)?

The mathematical constant π is used in a wide variety of fields. Besides of course mathematics, its utility spans science, engineering, and technology fields. Below I have listed a few examples of applications of Pi in various fields:

In Geometry, π is used to calculate the circumference and area of a circle, which are important concepts in geometry. The formulas for the circumference and area of a circle involve π.

In Trigonometry, π is used to define the relationship between the circumference and diameter of a circle. The value of Pi is also used to define the trigonometric functions such as sine, cosine, and tangent.

In Calculus, π is used to calculate the area under a curve, which is known as integration. The formula for the area under a curve involves π.

π is used in Statistics to calculate the normal distribution of data. The normal distribution curve is a bell-shaped curve that is defined using π.

In Physics π is used to calculate the frequency of waves and oscillations, which are important concepts in the study of waves and vibrations.

π is used in Engineering to calculate the dimensions of circular objects, such as pipes, gears, and wheels. The value of π is also used to calculate the volume of a cylinder.

In Computer science, π is used to generate random numbers, as applied in cryptography, simulation, and gaming.

In addition to these applications, π has also inspired artistic and cultural expressions, such as music, literature, and film. The study and application of Pi have contributed to many important discoveries and innovations throughout history and continue to inspire new ideas and advancements in science and technology.

## Did Mr. William Jones father π?

Mathematicians’ world over have known the mathematical constant π for several centuries. But, Mr. William Jones, a Welsh mathematician, takes the credit of assigning the symbol π to this mathematical constant. Sometimes in 1706, Mr. Jones chose this Greek letter π, because π (pronounced – pie) is the first letter of the Greek word perimitros, which means perimeter. Since π is used in the study of circles, he chose this symbol. So, if naming takes the credit, we can say Mr. William Jones fathered π. Name and naming matter, I suppose.

## Let us find out how mathematicians arrived at the value of Pi (π) to be 22/7? ## How π got its Value of approximately 3.14 or 22/7?

π is defined as the Circumference of a circle divided by the diameter of the circle. It is found to be constant.

I will use a wheel to explain. Let us take a wheel of 1 meter diameter. Now you have two options to measure the circumference.

1. Use a measuring tape, trace the circumference and find its length. Alternately,
2. 2 cut the circle open, lay it flat and measure the length of the circle which now is a straight line. In either case you will get a similar value expressed in meter. The value is determined to be 3.14 m or 22/7.

Accordingly, the circumference of a wheel of 2 m diameter will measure 6.28 m. Applying the formula, you will arrive at 3.14.

Let us continue this by an increment of 1 until you reach the diameter of 7 meters.

 3 m diameter wheel = 9.42 rounded to the whole number = 9 9/3=3 4 m diameter wheel = 12.56 rounded to the whole number = 13 13/4=3.25 5 m diameter wheel = 15.70 rounded to the whole number = 16 16/5=3.2 6 m diameter wheel = 18.84 rounded to the whole number = 19 19/6=3.16 7 m diameter wheel = 21.98 rounded to the whole number = 22 22/7=3.14

3 m diameter wheel = 9.42

rounded to the whole number = 9

9/3=3

4 m diameter wheel = 12.56

rounded to the whole number = 13

13/4=3.25

5 m diameter wheel = 15.70

rounded to the whole number = 16

16/5=3.2

6 m diameter wheel = 18.84

rounded to the whole number = 19

19/6=3.16

7 m diameter wheel = 21.98

rounded to the whole number = 22

22/7=3.14

A 7-meter diameter gives near close value to 3.14 and allows the possibility for infinite post decimal digits. Therefore, the value 22/7 is preferred over 3.14.

Fun Fact !

π is roughly approximated to few digits,

π =3.14159265...

The decimals can continue indefinitely. Mathematicians could not find any discernible pattern digits even after being calculated to over 100 trillion digits.

In conclusion, it is clear that Pi (π) is a fascinating constant that is fundamental to mathematics. π can be used to calculate complex equations and solve numerous STEM problems. Ultimately, understanding this number helps us better understand the world we live in and its math-based patterns. This March 14th, join the celebration for Pi day around the world and remember the invaluable role 'Pi' plays in our lives. If you’d like to learn more exciting facts about the important mathematical constant of Pi, don't forget to check out our blogs! You never know what interesting details you might find there.

Author: Ms. Surya Murugan, She studied math in college. She has always been curious about doing crafts and study it online and put it into practice. She like to do Writing neatly and using different fonts is her favorite thing.

Mrs. Emimmal Sekar Proofread this article. Mr. Arikaran Kumar manages the website and the social media outreach.