
stackexchange.com
https://english.stackexchange.com/questions/208040…
punctuation - English Language & Usage Stack Exchange
In the United States, most style guides that I have encountered recommend including the second hyphen in situations such as "8-foot-long bridge." Here is how some guides frame their advice. From The Associated Press Stylebook (2002): dimensions Use figures and spell out inches, feet, yards, etc., to indicate depth, height, length, and width. Hyphenate adjectival forms before nouns. [Relevant ...