what is pie?

Question

let me know...

Answer 1

Pie is a baked food having a filling of fruit, custard, meat, pudding, etc., prepared in a pastry-lined pan or dish and often topped with a pastry crust:

Pi is a a number equal to the ratio of a circle's circumference to its diameter.

Answer 2

By definition, pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter which circle you use to compute it.

For the sake of usefulness people often need to approximate pi. For many purposes you can use 3.14159, which is really pretty good, but if you want a better approximation you can use a computer to get it. Here's pi to many more digits: 3.14159265358979323846.

The area of a circle is pi times the square of the length of the radius, or "pi r squared":
A = pi*r^2

Pi is a very old number. We know that the Egyptians and the Babylonians knew about the existence of the constant ratio pi, although they didn't know its value nearly as well as we do today. They had figured out that it was a little bigger than 3; the Babylonians had an approximation of 3 1/8 (3.125), and the Egyptians had a somewhat worse approximation of 4*(8/9)^2 (about 3.160484), which is slightly less accurate and much harder to work with. For more, see A History of Pi by Petr Beckman (Dorset Press).

The modern symbol for pi was first used in our modern sense in 1706 by William Jones

Answer 3

ok...since this is in the mathematics section...i take it that you meant pi...not pie...as that should/would be in the food section...
a pi is the number that the diameter of a circle of any size going around the circle...in other words...if you take a piece of string, make it the length of the diameter of any circle and then make a few more...and place them end to end around the circle...what do you notice? no matter what size the circle is...the number of string you always need is just more than 3 and less than 4...and that number will be 3.141592654 often memorised in 3 significant figures of 3.14. hence this led to the formulation of how to calculate the circumference of a circle (length of the side of the circle) as
p ix diameter
- or -
pi x radius x 2 <-- (since radius is half of diameter)

Answer 4

Pie is use to culculate the area or circumference of a circle.
Pie x Radius of Circle x Radius of Circle = Area of Circle
Pie x 2 x Radius of Circle = Circumference od Circle

Pie = 3.142 or 22/7

Answer 5

By the derinition,Pi is the ratio of the circumference of a circle to deameter.Pi is always the same number, no matter wich circle you use to compute it.


The modern symbol for Pi was first used in our modern day textbooks....it was invented by William Jones in 1706

Answer 6

'pie' is a mathematical term for the fraction 22/7

Answer 7

IT IS NOT PIE BUT RATHER PI

The letter π

The name of the Greek letter π is pi, and this spelling is used in typographical contexts where the Greek letter is not available or where its usage could be problematic. When referring to this constant, the symbol π is always pronounced like "pie" in English, the conventional English pronunciation of the letter.

The constant is named "π" because it is the first letter of the Greek words περιφέρεια 'periphery' and περίμετρος 'perimeter', i.e. 'circumference'.

π is Unicode character U+03C0 ("Greek small letter pi").

Definition
Area of the circle = π × area of the shaded square
Area of the circle = π × area of the shaded square

In Euclidean plane geometry, π is defined either as the ratio of a circle's circumference to its diameter, or as the ratio of a circle's area to the area of a square whose side is the radius. The constant π may be defined in other ways that avoid the concepts of arc length and area, for example as twice the smallest positive x for which cos(x) = 0.[1] The formulæ below illustrate other (equivalent) definitions.

Numerical value

The numerical value of π truncated to 50 decimal places is:

3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510

See the links below and those at sequence A00796 in OEIS for more digits.

While the value of pi has been computed to hundreds of millions of digits, practical science and engineering will rarely require more than 100 digits. As an example, computing the circumference of a circle the size of the Milky Way with a value of pi truncated at 40 digits would produce an error margin of less than the diameter of a proton. On the other hand, occasionally to produce accurate final results, some calculations may require more accurate intermediate values. Even so, a value of pi longer than a few hundred digits should never be necessary.[2] The exact value of π has an infinite decimal expansion: its decimal expansion never ends and does not repeat, since π is an irrational number (and indeed, a transcendental number). This infinite sequence of digits has fascinated mathematicians and laymen alike, and much effort over the last few centuries has been put into computing more digits and investigating the number's properties. Despite much analytical work, and supercomputer calculations that have determined over 1 trillion digits of π, no simple pattern in the digits has ever been found. Digits of π are available on many web pages, and there is software for calculating π to billions of digits on any personal computer. See history of numerical approximations of π.

Calculating π

Most formulas given for calculating the digits of π have desirable mathematical properties, but may be difficult to understand without a background in trigonometry and calculus. Nevertheless, it is possible to compute π using techniques involving only algebra and geometry.

For example, observing a right angle isosceles triangle and noting that

\tan \left ( \frac{\pi}{4} \right ) = 1

yields:

\pi = 4\left(1-\frac{1}{3}+\frac{1}{5}-\frac{1}{7}+\frac{1}{9}-\frac{1}{11}\cdots\right)

This series is easy to understand, but is impractical in use as it converges to π very slowly. It requires more than 600 terms just to narrow its value to 3.14 (two places), and billions of terms to achieve accuracy to ten places.

A much more convergent, but slightly more complex, series is obtained by observing an equilateral triangle and noting that

\sin \left ( \frac{\pi}{6} \right ) = \frac{1}{2}

which yields:

\pi = 3 \sum_{n=0}^\infty \frac{(2n)!}{n!^2 (2n+1) 2^{4n}} = 3 + \frac{1}{8} + \frac{9}{640} + \frac{15}{7168} + \cdots

A ten figure accuracy is obtained with just the first 14 terms.

Measuring π

One common classroom activity for experimentally measuring the value of π involves drawing a large circle on graph paper, then measuring its approximate area by counting the number of cells inside the circle. Since the area of the circle is known to be

A = \pi r^2\,\!,

π can be derived using algebra:

\pi = \frac{A}{r^2}\,\!.

For a further explanation of this method as well as more computation methods see computing π.

Properties

The constant π is an irrational number; that is, it cannot be written as the ratio of two integers. This was proven in 1761 by Johann Heinrich Lambert.

Furthermore, π is also transcendental, as was proven by Ferdinand von Lindemann in 1882. This means that there is no polynomial with rational coefficients of which π is a root. An important consequence of the transcendence of π is the fact that it is not constructible. Because the coordinates of all points that can be constructed with compass and straightedge are constructible numbers, it is impossible to square the circle: that is, it is impossible to construct, using compass and straightedge alone, a square whose area is equal to the area of a given circle.

Answer 8

22/7

Answer 9

If you take a circle and somehow unwind it (suppose it is made of string) and measure its length you will find that if you also measure the length of the diameter and divide the two the number you get (approximately 3.14159....) will be the same for any circle you do this for--no matter how big or how small.

Answer 10

Pi is a mathematical symbol that is used to represent the number 3.141592654 often rounded to 3.14