[45 sec read]
Geometry Problems: Just about any calculations involving circles; the volume of a soda can to the orbits of satellites. Circumference and area of a circle are 2 * π * r and π * r^2 where r is the radius.
Signal Processing: Useful in studying curves. helps us understanding periodic or oscillating systems, electromagnetic waves, even music. Sine waves have a fundamental period of 2 * π.
Probability and statistics: π is used in the equation to calculate the area under a normal distribution curve, figuring out distributions of standardized test scores, margins of errors in scientific results, etc.
Biology and biometrics: The double helix in DNA revolves around π. π is in the pupil of the eye and helps study the structure of DNA, eye, etc.
Navigation: π comes into picture when calculating flight paths, as they fly in arcs and locating yourself using global position systems, etc.