In maths and science, which two letters are used for the number 3.1415?

Question should be "Which Greek letter is used for 3.14159..." not which 2 letters.

TerryThai, Approximated, you mean.

007, It should also be noted that this number is calculated using the fraction 22/7

Hated maths at school but do love a nice Pi! Pardon the pun lol