"We hid Lola's birthday present under the bed" is a prepositional phrase, it modifies a noun or a verb in the sentence with a preposition. In this case the phrase is an adverbial phrase because the preposition "under" is modifying the verb "Hid". If you ask Where the present was hidden? Was hidden under the bed.
"The runner leading the pack is our friend Kirsten" is a noun phrase, this phrase has a Noun, which is "Kirsten" but we can only identified who is Kirsten because of the rest of the prhase. Our friend kirsten is the runner leading the pack.
"The construction workers are building a new house" is a verb phrase, it is composed of the verb to be + ing form (are + building), and gives the idea of continuity. Because of the verbal structure used, is posible to identify that the workers are doing something in a cotinous way instead of a finished action or a reported action, for example.