Circumference and Area of the Circle

 

Formulas for a circle with radius r:

Circumference:
u = 2 r p
Area:
A = r2 p

Number p:

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