In a four-stanza poem the author can select along fifteen rhyme schemes such as aaaa, aaab, aaba, aabb, aabc, abaa, abab, abac, abba, abbb, abbc, abca, abcb, abcc, and abcd. You obtain the scheme for this one with the following exercise, each letter is assigned to the sound at the end of the sentence:
Roses are red, (A)
violets are blue, (B)
dodoes are dead, (A)
and that's a shame. (C)
The poem scheme is ABAC