So when do we use Pi in real life? drawing machining plans planes buildings & bridges geometry problems radio TV radar telephones estimation simulation global paths & global positioning space science & orbit calculation space ships satellitesGeometry problems: drawing, machining, etc.For instance, for everything from fitting equipment in, to line-of-sight calculations. Additionally, pi comes up in machining parts foraircraft; for instance, you might need a circular slot for mounting acamera that has a certain radius and a certain arc length.Signals: radio, TV, radar, telephones, etc.You have probably heard of sine waves. Well, sine waves have afundamental period of 2*pi, so pi becomes vital in signalprocessing, spectrum analysis (finding out what frequencies are ina wave you receive or send), etc.Probability: estimation, testing, simulation.Everyones favorite distribution (normal or Gaussian) has pi in theformula, and it is used in all areas of engineering to simulateunknown factors and loading conditions.Navigation: global paths, global positioning.When planes fly great distances they are actually flying on a arc ofa circle. The path must be calculated as such in order toaccurately gauge fuel use, etc. Additionally, when locating yourselfon a globe, pi comes into the calculation in most methods.