By definition, pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter which circle you use to compute it. For the sake of usefulness people often need to approximate pi.
Definition and Examples of Literary Terms. The term palindrome is derived from two Greek words âpalinâ means again and âdromosâ means way or direction. It is defined as a number, a word, a sentence, a symbol or even signs that can be read forward as well as backward or in reserve order with the same effects and meanings.
Palindromes. A palindrome is a sequence of letters and/or words, that reads the same forwards and backwards.  able was I ere I saw elba  is a palindrome. Palindromes also occur in DNA.There are two types.. Palindromes that occur on opposite strands of the same section of DNA helix. 5' GGCC 3' 3' CCGG 5'. This type of palindrome serves as the target for most restriction enzymes. The graphic shows the palindromic sequences seen by five restriction enzymes (named in blue) commonly used in recombinant DNA work.