**Pi is the
ratio of the circumference of a circle to its diameter.
This ratio has been useful not only for computation of circumference of
circles, but in many other geometric and mathematical computations. These
include areas of circles and ellipse, as well as volumes of spheres and
ellipsoids. **
**Approximation of pi has began as early as the ancient times. One of
the well-known one was by the great Greek mathematician Archimedes, who
started approximating Pi by inscribing a hexagon into a circle. With
the hexagon, pi was calculated to have a value of 3. Doubling the number
of sides and inscribing a dodecagon in the same circle, his new value
became closer to pi. He continued until he used a 96-gon, and found a
better approximation of 3.1419. A Chinese mathematician Lui Hui took
Archemedes' method farther. He used a 3,072-gon and approximated pi
to have a value of 3.1416, a very good approximation.**
**The value of Pi to the 20th decimal place
is**
**
3.14159 26535 89793 23846**
**More Mathematical Recreations** |