The circumference of a circle is found by using the equation: C= 2 x PI x r
Both circles have r = 1
Circumference = 2x 3.14 x 1 = 6.28.
Diameter is 2 times the radius= 2x1= 2
The ratio of the circumference to the diameter = 6.28 / 2 = 3.14 which is the value of PI
