Street Parking: Metered parking available on Charles St. $1.25 per hour; 2 hour maximum before having to move to a different meter. Valet parking: Available starting at 5 PM daily. Valet charge is $20. Garage Parking: Boston Common Parking Garage- Charles St./Beacon St. corner of garage.
By definition, pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter which circle you use to compute it. For the sake of usefulness people often need to approximate pi.
Pi is the ratio of a circle's circumference to it's diameter. It's useful for working out various things about a circle. For example, Where R is the radius of a circle and D is the Diameter (D = 2R), piRSquared will give you the area and piD gives the circumference.