Let's start with a few definitions. The circumference of a circle is the measurement of the whole circle, the outside of the circle. The diameter of a circle is the greatest width of the circle or twice the radius of a circle, which is the midpoint of the circle to the edge. By knowing either the diameter of the circle of the circumference, you can determine the other. For instance, the diameter of the circle multiplied by the pi, which is 3.1415... will get you the circumference of a circle. I am sure that there are other formulae, but this should give you a good start.

Circumference equals Pi (3.14) times the diameter (diameter is 2 times the radius) or simply 2 times Pi times the radius.

I always taught my math students that if you have a circle (circumference) of friends you can "Party (or Pi-D). Corny but it worked. Good luck!

The circumference of a circle is is always pi times the diameter of the circle. Or if C is the circumference of circle and d is the diameter of the circle, then the relationship between the circumference and the diameter is given by:

C = pi*d, where the value of pi = 3.141593654 approximately.

Also if r is the radius of thr circle, fixed distance distance from the centre of the circle to anny point on the circumference of the circle, then r = d/2. Therefore, C = pi*d = 2pir. Or the circumference is equal to 2 pi times radius of the circle.

**TT (often written pi) is a mathematical constant whose value is the ratio between circumference and diameter of any circle in a Euclidean space**, is the same value as the ratio of area of a circle and square of its radius.

**pi=2*pi*R/2*R, where 2*pi*R=circumference of any circle and 2*R=D=diameter of any circle.**

The symbol "pi" was first proposed by Welsh mathematician William Jones, in 1706. Constant value is equal to approximately 3.14159, in an ordinary decimal notation.

**Pi** is one of the most important constants in mathematics and physics: many formula of mathematics, engineering and other sciences involving **pi.**

Since pi is an irrational number, it has an infinite number of decimals that do not contain sequences that are repeated. The infinite string of digits has fascinated mathematicians and many have made significant efforts over the past several centuries to calculate decimal places and to investigate properties of this number. Despite the analytical work and calculations performed on supercomputers have calculated 10 thousand billion digits of π, there appeared no identifiable pattern in the digits found.