Final answer:
The meter of 'Sir Gawain and the Green Knight' is characterized by lines with strong stresses, often using iambic tetrameter or iambic pentameter.
Step-by-step explanation:
The meter of 'Sir Gawain and the Green Knight' is defined by alliterative lines with strong stresses, typically found in the form of iambic tetrameter or iambic pentameter. This epic poem is a notable example of Middle English literature that utilizes a distinct metrical structure and strong rhythm through the use of stressed syllables. Unlike free verse, which lacks a regular meter, the poem is set in a structured rhythmical pattern that enhances its narrative flow and dramatic impact.