Many people like using pi tapes to measure the pipe size. Pi tapes, which wrap around the pipe the same way but have units in diameter, can be expensive. With calculators everywhere today, dividing by 3.14 is a snap, making these pi tapes not even necessary.
Fuck is an obscene English-language word, which refers to the act of sexual intercourse and is also commonly used as an intensifier or to denote disdain. Its origin is obscure but is usually considered to be first attested to around 1475, although it may be considerably older.
K means 1,000 Prolly means he has thousands of dollars. As others have said, k in this case likely means 1000. Like 256k of memory would be 256,000 bytes of memory. If they are talking about money, 10k would be $10,000 dollars. The k is for kilo which comes from the Greek word khiloi, their word for thousand. K or Special K is street slag for ketamine, a powerful prescription drug that is often available illegally for recreational use. It's basically a horse tranquilizer. In chemistry, K is the element potassium, which shows up in geology sometimes.