- William Jones is credited with first using the symbol π in 1706 to represent the ratio of a circle's circumference to its diameter, which had previously been undefined. - Archimedes was one of the first to calculate an approximation of pi, determining that 223/71 < π < 22/7. - Pi Day is celebrated on March 14th in recognition of the first three digits of pi in decimal form - 3.14. Some also celebrate Pi Approximation Day on July 22nd due to the common approximation of 22/7.

3. The number π is a mathematical constant, the ratio of
a circle's circumference to its diameter, approximately equal to
3.141592. It has been represented by the Greek letter "π" since the
mid-18th century though it is also sometimes spelled out as "pi"
The symbol used by mathematicians to represent the ratio
of a circle's circumference to its diameter is the Greek
letter π, sometimes spelled out as pi. In
English, π is pronounced as "pie" In mathematical use, the
lower-case letter π (or π in sans-serif font) is distinguished
from the capital letter Π, which denotes a product of a
sequence.

4. That the ratio of the circumference to the diameter of a circle is constant
(namely, pi) has been recognized for as long as we have written records.
The first theoretical calculation of a value of pi was that of Archimedes
of Syracuse (287-212 BCE), one of the most brilliant mathematicians of
the ancient world. Archimedes worked out that 223/71 < < 22/7.
Archimedes's results rested upon approximating the area of a circle based
on the area of a regular polygon inscribed within the circle and the area
of a regular polygon within which the circle was circumscribed.
Beginning with a hexagon, he worked all the way up to a ploygon with
96 sides!

5. A mathematics teacher named William Jones is credited with first using
the symbol ? in 1706 to represent the concept of the ratio between a
circle's circumference and diameter. It had previously been ill-defined.
Prior to Jones' usage of the ? symbol, the ratio of a circle's
circumference and diameter was known as "the quantity which, when
the diameter is multiplied by it, yields the circumference." William
Jones first used the symbol in his book, "Synopsis Palmariorum
Matheseos, or A New Introduction to the Mathematics." Jones believed,
but could not prove, that pi was irrational.
WilliamJones andhis Circle: The Man who invented Pi

6. •Jones believed, but could not prove, that pi was irrational.
In 1761, Johann Lambert first proved that pi was an
irrational number.
•There are many people how gave the value of but
Aryabhatta gave appox vale of pi

7. Some approximations of pi include:
•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 50 decimal digits
are 3.14159265358979323846264338327950288419716939937510
•Binary: The base 2 approximation to 48 digits
is 11.001001000011111101101010100010001000010110100011...
•Hexadecimal: The base 16 approximation to 20 digits
is 3.243F6A8885A308D31319...
•Sexagesimal: A base 60 approximation to four sexagesimal digits is
3;8,29,44,1

8. Digits of Pi
First 100 digits
3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164
0628620899 8628034825 3421170679 ...
First 1000 digits
3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164
0628620899 8628034825 3421170679 8214808651 3282306647 0938446095 5058223172
5359408128 4811174502 8410270193 8521105559 6446229489 5493038196 4428810975
6659334461 2847564823 3786783165 2712019091 4564856692 3460348610 4543266482
1339360726 0249141273 7245870066 0631558817 4881520920 9628292540 9171536436
7892590360 0113305305 4882046652 1384146951 9415116094 3305727036 5759591953
0921861173 8193261179 3105118548 0744623799 6274956735 1885752724 8912279381
8301194912 9833673362 4406566430 8602139494 6395224737 1907021798 6094370277
0539217176 2931767523 8467481846 7669405132 0005681271 4526356082 7785771342
7577896091 7363717872 1468440901 2249534301 4654958537 1050792279 6892589235
4201995611 2129021960 8640344181 5981362977 4771309960 5187072113 4999999837
2978049951 0597317328 1609631859 5024459455 3469083026 4252230825 3344685035
2619311881 7101000313 7838752886 5875332083 8142061717 7669147303 5982534904
2875546873 1159562863 8823537875 9375195778 1857780532 1712268066 1300192787
6611195909 2164201989

9. Why is pi equal to 3.14159?
As everybody knows pi=L/(2*R)=L/D is the ratio of
the circumference to the diameter for any circle. It is
an irrational and transcendental number and since now
we have discovered over 10^12 digits of it. But pi is
the 'governor' of the geometry of our local universe
and is apparent everywhere, even in the general
relativity main equation. The question is very simple:
Why is pi=3.14159? Which is the Law of the Laws?

10. Pi Day
Pi Day is an annual American celebration
commemorating the mathematical constant π (pi). Pi
Day is observed on March 14, since 3, 1, and 4 are the
first three significant digits of π in decimal form. In
2009, the United States House of
Representatives supported the designation of Pi Day.
Pi Approximation Day is observed on July 22, since
the fraction 22⁄7 is a common approximation of π,
which dates from Archimedes.

11. 1. Some also celebrate July 22 as Pi Day, because 22/7 is a common
approximation to pi.
2. Pi is an irrational number: its decimal value goes on for ever, never stopping
or repeating.
3. The value of pi has now been calculated to more than two trillion decimal
places.
4. The world record for memorising the value of pi was set by Chao Lu of
China in 2005. He correctly recited from memory its first 67,890 digits.
5. If you write “3.14” on a piece of paper and hold it up to a mirror, it looks
like the word “PIE”.
Facts about Pi