Question

So oft as I her beauty do behold, And therewith do her cruelty compare, I marvel of what substance was the mould The which her made at once so cruel-fair. Now read the lines from Shakespeare's "Sonnet 131." Thou art as tyrannous, so as thou art, As those whose beauties proudly make them cruel; For well thou know'st to my dear doting heart Thou art the fairest and most precious jewel. The idea in the sonnets are similar because both sonnets focus on

Answer 1

They are both speaking about how beautiful women are harsh and cruel. 

The sonnet states, Soft as her beauty do behold, the writer is talking about how beautiful she is and speaking of the woman highly, and then you have the next line, And therewith do her cruelty compare. 

Then you have the next sonnet, As those whose beauties proudly make them cruel; and then you have Thou art as tyrannous, so as thou art,