Which section of sonnet 130 has a cdcd rhyme scheme?

The poetic metric consists of a scheme to rhyme verses in a poem. Usually, the most important word is the last one, which needs to rhyme with the last word of another verse.

These schemes come in many forms, and we simplify them using letters of the alphabet, i. g. aabb, acac etc.

These letters represent a phoneme, chose arbitrally.

For example, in sonnet 130, we have the following sheme:

"My mistress' eyes are nothing like the sun;

Coral is far more red than her lips' red;

If snow be white, why then her breasts are dun;

If hairs be wires, black wires grow on her head. "

In this sonnet by Shakespeare, "sun" rhymes with "dun", so we will call them "a", while "red" rhymes with "head", and we shall call them "b". The scheme of this stanza, therefore, is abab.

The poem continues:

"I have seen roses damask'd, red and white,

But no such roses see I in her cheeks;

And in some perfumes is there more delight

Than in the breath that from my mistress reeks."

Since we already have abab in the poem, "white" that rhymes with "delight" shall be named "c", while "cheeks" that rhymes with "reeks" called "d". Therefore, at last, we have the structure cdcd, that combined with the first part of the poem results in abab cdcd.