Circumference and Area of a Circle

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Formulas for a circle with radius r:

Circumference:u = 2 r π
Area:A = r2 π

Number π:

π = 3.1415926535 8979323846 2643383279 5028841971 6939937510
          5820974944 5923078164 0628620899 8628034825 3421170679 ...