I'm really having trouble figuring out how to describe a clause describing a subject which contains a comparative adjective (or an adjective of equality). For example:
Children [shorter than four feet] are not allowed on the ride.
Words [larger than eight letters] confuse me.
The number [equal to 6] is the correct answer.
Which word [synonymous with "sad"] is also a color?
Is this a relative clause without a relative pronoun? Also, would these clauses be considered non-restrictive, therefore requiring commas?