Chi (letter) for the design of steel structures. In graph theory, a lowercase chi is used to represent a graph's chromatic number. Chi (letter) Chi (uppercase Χ, lowercase χ; ) is the 22nd letter of the Greek alphabet, pronounced or in English. Its value in Ancient Greek was an aspirated velar stop (in the Western Greek alphabet: /ks/). In Koine Greek and later dialects it became a fricative (/) along with Θ and Φ. In Modern Greek, it has two distinct pronunciations: In front of high or front vowels ( or ) it is pronounced as a voiceless palatal fricative , as
V V V (named "vee" ) is the 22nd letter in the modern English alphabet and the ISO basic Latin alphabet. The letter V comes from the Semitic letter "Waw", as do the modern letters F, U, W, and Y. See F for details. In Greek, the letter "upsilon" 'Υ' was adapted from "waw" to represent, at first, the vowel as in "moon". This was later fronted to , the front rounded vowel spelled 'ü' in German. In Latin, a stemless variant shape of the upsilon was borrowed in early times as V—either directly from the Western Greek alphabet or from