What's the rhythm of ababcdcd?

Shakespeare wrote 154 sonnets, the most famous of which is 18 poem "Shall I compare them to a summer day", in which the meter is more rigorous. This poem can be divided into three quatrains and a set of couplets, with iambic pentameter as the rhythm and ababccdcd efefgg as the rhyme. This is the "Shakespeare Sonnets" which highlights the British characteristics.