60 miles an hour

[Shie0605]

60 miles an hour
six feet deep

All these are nouns.
What is the grammatical structure?
Thanks.

 

[emsr2d2]

@Shie0605 As I told you in your other post, a title such as "Test 2" is insufficient. Titles must be unique, relevant to the thread, and contain some/all of the words/phrases sentences you're asking us about. Use the "Edit" button to change your title to "60 miles an hour". After you do that, we will start to deal with your question.