English seems pretty flexible in allowing "measure expressions" to appear in positions modifying adjectives and determiners.
What are these things actually called? How are they usually analyzed?
1) The lake is forty miles wide. 2) My sister has twenty percent more money than I do.
Measure expressions can be somewhat complex, I think, but not arbitrarily complex.
3a) The boat is fifty or sixty feet long. 3b) #The boat is fifty feet long or sixty feet long. 4) The boat is fifty Roman feet long. 5) *The boat is fifty feet as defined in 1593 long.