Make a brief study of the structure and thematic pattern of the Shakespearean sonnet.
Your question doesn't name a specific Shakespearean sonnet so I'll answer generally.
The sonnet, of course, is a 14-line poem. Shakespearean sonnets are organized in three four-line stanzas (quatrains) followed by a concluding couplet. The turn of the poem occurs between the 12th and 13th lines, between the end of the quatrains and the couplet. The closing couplet can serve as a summary of what comes before, but can also conclude the poem in some other way. It usually resolves, restates, or redifines the central situation or problem in the poem. Unity of theme, of course, would be expected, with the couplet in some way tying the theme together.
The rhyme scheme is: abab cdcd efef gg. You can see the rhyming couplet follows the quatrains.
this is a question set by the gauhati university, correspondence school, I was also looking for the answer. Thanks to the teacher for the information. But I think in case of Masters, and espicially when someone is preparing a seminar/home assignment, this answer will not do.