Which line structure is not typically associated with a haiku?

The line structure that is not typically associated with a haiku is characterized by two lines of iambic dimeter. Haikus are traditionally composed of three lines with a specific syllable structure of 5-7-5, which means the first line contains five syllables, the second line has seven syllables, and the third line returns to five syllables. Additionally, haikus often focus on themes of nature or seasonal changes, further reinforcing their distinct style.

The syllable count in a haiku is indeed fixed, making it essential for the poem's structure and rhythm. The combination of a strict syllable count along with its evocative imagery and connection to nature sets haikus apart from other poetic forms, such as those that might use iambic dimeter, which has a different structure and does not adhere to the haiku format.