Final answer:
The absolute phrase in the sentence is "his loud laughter carrying across the school." It provides additional context to the main clause about how Sam could be heard.
Step-by-step explanation:
The absolute phrase in the sentence "Sam could be heard all the way down the hall, his loud laughter carrying across the school." is "his loud laughter carrying across the school." An absolute phrase is a group of words that modifies an independent clause as a whole.
This phrase typically consists of a noun or pronoun, a participle, and any associated modifiers. Absolute phrases provide additional information about the situation or context and are often set off by commas.
In this example, "his loud laughter" is the noun, and "carrying across the school" is the participle phrase that modifies the main clause, providing a vivid description of how audible Sam's laughter was. It adds detail to the action of Sam being heard without directly altering any specific word in the main clause.