In view of the coronavirus pandemic, we are making LIVE CLASSES and VIDEO CLASSES completely FREE to prevent interruption in studies
Home > Formulas > Maths Formulas > Pi Formula
Maths Formulas

Pi Formula

Pi is a very important constant in mathematics as well as in science which is widely in use. On the other hand, we may say that Pi is a really straightforward number. It is represented with symbol Π. The calculation can be done in many ways. It is used and hence can be computed with a variety of methods. In this topic, the student will learn the Pi formula. Let us learn it!

Pi Formula

Concept of Pi

Pi refers to the ratio of the circumference to the diameter of a circle. So its approximate value is 3.14159 and often shortened to 3.14. The decimal in Pi never ends because the numbers never repeat themselves in a permanent pattern. Due to this fact, the number repeats it is not possible to find a circle’s true circumference or area. The record for calculating Pi is with 5 trillion digits! The closest fraction to represent Pi is found to be \(\frac {22}{7}\). But even this is not completely accurate.

The first calculations of Pi were done in the Babylonians in 2000 BC who determined it as 3.125. Further, the Ancient Egyptians came to the conclusion that it was 3.143. Then Plato determined it to be 3.146. Later on, Isaac Newton, who is considered to be calculus’ father, was able to calculate Pi to 16 decimal points.

Pi Formula

Facts about Pi

  1. Rhind Papyrus made the first attempt to try and calculate pi. He built a square inside a circle to calculate the diameter.
  2. The symbol for Pi was introduced by William Jones in the year 1706.
  3. The first 36 digits of Pi are the Ludolphine Number. This number was named after Rudolph Van Ceulen who spent the majority of his life calculating the first 36 numbers.
  4. We celebrate Pi Day on 14th of March every year. Thus, we represent this date numerically by \(\frac {3} {14}.\)
  5. There are no zeros in the first 31 digits of Pi.
  6. Some mathematicians believe that it is better to say that circles have an infinite number of corners than to say that they have zero corners

Therefore, Pi i.e. \(\pi\) is the first number we learn as an irrational number. It is a mysterious number which has digits which go on forever and has fascinated people for many years. We learn that we can start to write down it as 3.141592653589….. but that we can never finish it.

Pi is also a really useful number. It appears everywhere in mathematics and also almost countless times in Engineering and Science.

Some Formulas in Mathematics that includes Pi

We define the number \(\pi\) mathematically as follows:

\(\pi = \frac {c}{d}\)


\pi Constant
d diameter
c circumference

Other formulas are:

  1. The circumference of a circle with radius r is \(2 \pi r.\)
  2. We denote the area of a circle with radius r as \(\pi r^2.\)
  3. The volume of a sphere with radius r is \(\frac {4}{3} \pi r^3.\)
  4. The surface area of a sphere with radius r is\( 4 \pi r^2.\)

Solved Examples for Pi Formula

Q.1: Compute the value of \(\pi\), if a circle has a radius as 7 cm and circumference as 44 cm.

Solution: Given here:

c = 44 cm

d = \(2 \times 7 = 14 cm\)

Also, formula is,

\(\pi = \frac {c}{d} = \frac {44}{14}\)

= 3.142857142…..

Share with friends

Customize your course in 30 seconds

Which class are you in?
Get ready for all-new Live Classes!
Now learn Live with India's best teachers. Join courses with the best schedule and enjoy fun and interactive classes.
Ashhar Firdausi
IIT Roorkee
Dr. Nazma Shaik
Gaurav Tiwari
Get Started

Leave a Reply

Notify of

Stuck with a

Question Mark?

Have a doubt at 3 am? Our experts are available 24x7. Connect with a tutor instantly and get your concepts cleared in less than 3 steps.
toppr Code

chance to win a

study tour

Download the App

Watch lectures, practise questions and take tests on the go.

Get Question Papers of Last 10 Years

Which class are you in?
No thanks.