2. Pi (π)
• Pi is the ratio of a circles circumference to its
diameter.
• Therefore, Circumference/Diameter = Pi
• The circumference is proportional to the
diameter and therefore Pi remains constant.
• A sphere is similar to a circle, except it is a
three dimensional shape, and therefore Pi is
applied to spheres.
3. The Basketball
• This is a simple glow in the dark basketball
that I bought for myself a few years ago. I have
always loved it and taken care of it. I always
liked it because its glow in the dark and
bounces pretty darn high (for a basketball).
Now its being used as a school project.
Sacrifices must be made.
4. The Basketball (continued)
Pi is written on the ball, to the extent of :
3.1415926535897932384626433832795028841971693993751058209
7494459230781640628620899862803482534211706798214808651
3282306647093844609550582231725359408128481117450284102
7019385211055596446229489549303819644288109756659334461
2847564823378678316527120190914564856692346034861045432
6648213393607260249141273724587006606315588174881520920
9628292540917153643678925903600113305305488204665213841
4695194151160943305727036575959195309218611738193261179
3105118548074462379962749567351885752724891227938183011
9491298336733624406566430860213949463952247371907021798
60943702770539217176293176752384674818467669405132000568127
145263560827785771342757789609173637178721468440901
224953430146
7. My sphere (the basketball)
• Since the diameter is 9 inches, the radius must
be 4.5 inches. Therefore, by the given formula,
the Surface area is 81π inches squared, or 254
inches squared. (4×π×4.52)
• The volume is (243/2)π inches cubed, or 381
inches cubed. ((4/3)×π×4.53)
• And finally, the circumference is 9π inches, or
28.3 (which is very close to my measurement
of approximately 29 inches). (2×π×4.5)
8. Conclusion
• Pi is very important for determining the areas
of spheres, circles, angles, sectors, arcs, and
many other applications.
