Pi

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Pi
By Jihye Choi

• Questions
• What is Pi?
• What is the history of pi?
• How is Pi used?
• How many numbers/digits are in Pi? Does it ever
  end?

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What is Pi?

• Pi is an infinite decimal. Pi is the number of
  times a circle's diameter will fit around its
  circumference.
• Circumference

3
How the infinite decimal started..

• People have studied Pi for thousands of years.
  The ancient Egyptians and Greeks knew about the
  number. By 1701 The first 100 numbers of Pi had
  been calculated.
• They are, 3.1415926535 8979323846 2643383279
  5028841971 6939937510 5820974944 5923078164
  0628620899 8628034825 3421170679 ...

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The Greek Alphabet

• If you dont know much about Pi you will probably
  be wondering what this has to do with it, well,
  Pi is the 16th letter of the Greek alphabet. In
  ancient Greece the symbol Pi denoted/represented
  the number 80.

Greek alphabet
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How is Pi used?

• Pi is used in many things, its mostly used in
  Science and Math.
• For example, Pi occurs in hundreds of equations
  in many sciences including the equations
  describing the DNA double helix, a rainbow,
  ripples spreading from where a raindrop fell into
  water and on and on

Ripples forming where raindrop fell into water.
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How many digits are in Pi? Does it ever end?

• Because Pi is known to be an irrational number it
  means that the digits never end or repeat in any
  known way.
• Digits known, never any way repeat

Pi
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-Interesting Facts-

• Pi day is celebrated on March 14th .
• The first person to use the letter Pi for the
  number was Welshman William Jones in 1706.
• The Pi champion is Hiryoki Gotu, who memorized
  42,000 digits.
• For a circle to equal Pi the diameter must equal
  one.

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-Dictionary-

• arc a curved line that is part of the
  circumference of a circle
• chord a line segment within a circle that
  touches 2 points on the circle.
• circumference the distance around the circle.
• diameter the longest distance from one end of a
  circle to the other.
• origin the center of the circle
• pi A number, 3.141592..., equal to (the
  circumference) / (the diameter) of any circle.
• radius distance from center of circle to any
  point on it.