Read the sentence below and determine which part contains a relative clause. the former college friends, who are five in number, reunite each year.

The Relative Clause is “who are five in number”. It is a type of dependant clause (it need the main clause in order to convey its meaning properly) that has the same function of an adjective; that is to say, it modifies a noun “friends”.

I think the relative clause would be who are five in number. Hope this helped