The meter of Edmund Spenser's The Faerie Queen is mostly iambic pentameter. That means each line contains a total of ten syllables. Those ten syllables are broken up into five different chunks called "feet." Each foot contains an unstressed syllable followed by a stressed syllable. That metric foot is the iambic foot, and there are five of them per line (pentameter).

I said that the poem is mostly written using iambic pentameter. Spenser regularly breaks that meter in line nine of each stanza. The iambic rhythm stays the same, but one extra foot is added in the ninth line. That gives the final line of each stanza a total of twelve syllables. Lines 1-8 of a stanza are written in iambic pentameter. Line 9 of a stanza is written in iambic hexameter.

The alphabetical lettering of the rhyme scheme of the two lines that the question displays is AA. The two lines end with the same sound, so the same two letters get used; however, those lines are part of an entire nine-line stanza. Within the actual full stanza, those lines should be labelled BB. That's because the stanza rhyme scheme in this poem is ABABBCBCC. The two lines in the question are lines 4 and 5 from that particular stanza.