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 16th letter of the Greek alphabet, but it is best known as the symbol used to name a mathematical relationship: the ratio between the circumference of a circle and its diameter. As such, it is a mathematical constant and has many uses.