2. PI: Food Group or Math Concept? Pi Day Presentation

3. What is Pi? Not to be confused with “pie,” which is eaten for dessert, Pi is defined as the ratio of the circumference to the diameter of a circle Pi is usually denoted with this Greek symbol: π

4. Is Pi Dependent on the Size of the Circle? Nope! Pi is a constant, which means its value does not change. This means that the ratio of the circumference to the diameter of one circle is exactly the same as the ratio of the circumference to the diameter of any other circle.

5. 3.141592551104866223558431126381048812355898112276391048823661691 12648104891237105711355110577023712221136511058672371277113652105 86823713861136671058762371496113682105891237171611369410589123723 75113696105806987498576984769847609873409867439857694387569803475 28937465283974658927364587923645897236458723645987236859742365298 76458726345897623897465283746587293465897236458726458972436952384 92322547392938475623987562897465298376598726549872365987236598726 87968197871987261987618719876187632198716239874168971236489761238 97641238976143298761911010101032178648764387263874687638763286234 23189432943213458745984753489760975645784326574365743256743657432 65743256743265743276543265743265743268743268743268743268732468742 38763468727364872364872634872634876238476287346872164872648726348 71623487216348762138746218764318726348712634876123876482173647126 34872163487621387462873647213648271364872136487126348726487126387 62487263847623876418276348716234871623874682734687126348721634872 61873461287364871263487126348761238746128736418732648712648754354 39875438935409453809543805349854309854309801010101029389813287243 87634287643287648723648762384762387462873648726348726348726348726 What is the “Value” of Pi? Pi is an irrational number – its decimal digits do not repeat but “go on forever” Mathematicians estimate digits of pi to use it in real world settings. Pi is usually rounded off to about 3.1415

6. Who Discovered Pi? In biblical times, some guessed that π was equal to 3, but that wasn’t very accurate. Archimedes was the first to theoretically approximate pi. He calculated that pi was “trapped” between 223 / 71 and 22 / 7, or roughly 3.1428. Today we use better approximations, most of which are derived by computers.

7. The Usefulness of Pi Pi is extremely useful for calculating the area and circumference of a circle: A = πr 2 and C = 2πr. Many disciplines of science use π in their equations (formulas) to describe the world. In fact, DNA, rainbows, the human eye, music, color, and ripples all have some natural roots in pi.

8. Hip to Be Square One interesting theorem related to pi deals with whether or not one can construct (with a compass and straight edge) a square with the same area as a given circle. That is, the red square on the left is equal in area to the small circle. This picture was not constructed using that method. Although such squares “exist,” it is not possible to construct them with a compass and straightedge because of the particular nature of pi.

9. The Big Five Pi helps link together the four other important numbers in math (e,i,0,1) in one equation: e πi +1=0 This equation is the result of the “Complex Exponential Function,” which is used in college mathematics

10. Pi Was Controversial ! Throughout history, people have been very passionate about math. In fact, some of the first mathematicians to consider the concept of “0” were executed for questioning the current system of thought (which at the time did not include the concept of “0”). An Indiana legislator tried to define pi as 3 but failed. The decision created an ugly yelling match between “traditionalists” and engineers.

11. Pi and the Arts A few have become so obsessed with the number π that they wrote poems about it: There once was a number Pi Very special like e and phi Circumference to d Is the ratio for me And it's not a multiple of I A 1998 movie about a code-cracker was named “Pi.”

12. Celebrate Pi Day, March 14th Yay!