What does the mathematic term pi mean?

Answer 1

The value of pi is 3.14159265 to 8 decimal places, and is related to the length of the radius from the centre point of the circle to the mid-point of the thickness or width of the drawn line of the circumference [or the thickness of the material a round container or cylinder could be made of]
The value of pi is slightly less if the radius measurement is to the internal edge of the line, or more if is measured to the external edge of the line or material