"A relative clause is another name for an adjective clause. This is because both perform a function similar to an adjective in a sentence--they add information to a noun.
There are two types of...
"While talking" is an adverb clause; it describes in what circumstance (how/when) the teacher knocked over his glass, the PM sneezed, the newscaster skilfully pointed out the fronts without even...
"That". In a non-restrictive adjective clause, such as in the sentence:
"He went to the Eiffel Tower, which is located in Paris."
The non-restrictive adjective clause, "which is located in...