SHERRI BROGDON

THE IRRATIONAL WORLD OF PI

DEFINITION AND VOCABULARY OF PI• Definition of pi is the ratio of the circumference to the diameter of a circle • The approximate area of the circle lies between the areas of the circumscribed

and the inscribed hexagons.• Pi is an irrational number – a number that never ends or never repeats.• Pi is approximately 3.14 or exactly 22/7.• Pi can be rounded to 3 only when answering multiple choice questions or

estimating.• Pi is a number used in the calculation of formulas for shapes with circular parts.

HISTORY OF PI• The first calculation of pi was done by Archimedes of Syracuse in

approximately 287–212 BC, that was a long time ago. ( 1)• Mathematicians began using the Greek letter π in the 1700s. (1)• Georges Buffon devised a way to calculate pi based on probability. We refer

to the illustration of this phenomena as Buffon’s Needle. (2)

USES OF PI

Circles:Spheres: Volume = 4r2

Cones:Cylinders:

WORK CITED

Information:

1. Exploratorium. (2013). http://www.exploratorium.edu/pi/history_of_pi/

2. Reece, G. (2014). Buffon’s needle: An analysis and simulation. Retrieved November 13, 2014 from http://mste.illinois.edu/activity/buffon/

Images:

http://www.ualr.edu/lasmoller/pi.html

http://www.mathfunny.com/pi-piday-joke/

http://3dshapes.org/3d-shapes-cylinder-shape.html

http://mkweb.bcgsc.ca/pi/art/