In poetry, an iambic foot is made up of an unstressed followed by a stressed syllable, such as "he sings." true false

True.

Explanation:

In poetry, the use of "iambs" as a meter form where the first syllable forms the unstressed part of the rhythm while the next syllable is the stressed part of the rhythm. In the above provided sentence "He sings", "he" is the unstressed syllable while like it is already written in the question, "SINGS" is already capitalized, thereby suggesting it is the stressed syllable. These two stressed and unstressed syllables are the most  important components of the metrical foot used in poetry.  "Iambs" represent the unstressed and stressed syllables in the poem in poetry.