The sentences are brief and of equal length.
I understand this form --> The sentences has equal length.
but NOT this one with "of" --> The sentences are of equal length.
The sentences are of equal length
subject phrase linking verb ??? ???
he is of smart?
he is (
a being with the quality of) smart?
why of? I am nervous when seeing " be + of "
I asked before (
) and
Mister Micawber has kindly explained to me. But I still don't get the usage of OF this the above sentence.