1.  Name : Şeyma
 Surname : Sevindik
 Student No : 20111399
 Departmant : IMAT
 Lesson : Eng 102
 Subject : Pi Day
 Teacher : Gulsen Husseın

2.  Definition of Pi
 Name of Pi
 Pi Day
 History of Pi Day
 Celebrates

4.  π is commonly defined as the ratio of circle’s cicum
ference C to its diameters d:
 The ratio C/d is constant, regardless of the
circle's size. For example, if a circle has twice the
diameter d of another circle it will also have twice the
circumference C, preserving the ratio C/d. This
definition of π is not universal, because it is only valid
in flat (Euclidean) geometry and is not valid in curved
(non-Euclidean) geometries.

5.  For this reason, some mathematicians prefer
definitions of π based on calculus or
trigonometry that do not rely on the circle.
 One such definition is; π is twice the smallest
positive x for which cosine (x) equals 0.

6.  The symbol used by mathematicians to represent the
ratio of a circle's circumference to its diameter is the
Greek letter π.
 That letter can be denoted by the Latin word pi, which
is also used to represent the same ratio.
 In English, π is pronounced as “pie”.
 The lower-case letter π (or π in sans-serif front) is not
to be confused with the capital letter Π, which denotes
a product of a sequence.

8.  Pi Day is an unofficial holiday commemorating
the mathematical constant π (pi).
 Pi Day is celebrated on March 14 (or 3/14
in month/day date format), since 3, 1 and 4 are the
three most significant digits of π in the decimal
from.
 In 2009. the United States House of
Representatives supported the designation of Pi
Day.

10.  Pi Approximation Day is held July 22 (or
22/7 in day/month date format), since
the fraction 22⁄7 is a common
approximation of π.

11.  The earliest known official or large-scale celebration of
Pi Day was organized by Larry Shaw in 1988 at the San
Fransisco Exploratorium, where Shaw worked as a
physicist, with staff and public marching around one
of its circular spaces, then consuming fruit pies. The
Exploratorium continues to hold Pi Day celebrations
 On March 12, 2009, the U.S. House of Representatives
passed a non-binding resolution (HRES 224),
recognizing March 14, 2009, as National Pi Day.

12.  For Pi Day 2010, Google presented a
Google Doodle celebrating the holiday,
with the word Google laid over images of
circles and pi symbols.

13.  There are many ways of celebrating Pi Day. These
include eating pie and discussing the significance
of number π.
 The Massachusetts Institute of Technogy has
often mailed its application decision letters to
prospective students for delivery on Pi Day.
 Starting in 2012, MIT has announced it will post
those decisions (privately) online on Pi Day at
exactly 6:28pm, which they have called "Tau
Time", to honor the rival numbers Pi and Tau
equally.

15.  The town of Princeton New Jersey hosts numeros
events in a combined celebration of Pi Day and
Albert Einstein’s birthday, which is also March 14.
Einstein lived in Princeton for more than twenty
years while working at the Institute for Advanced
Study.
 In additional to pie eating and recitation contests
there is an annual Einstein look-a like contest

16.  There are also some serious critical observations
by scientists that wind up examples of false
celebrations on the web.
 The New Scientist found several stimulating
starting points for true mathematical
celebrations

19.  http://en.wikipedia.org/wiki/Pi
 http://en.wikipedia.org/wiki/Pi_Day