Final answer:
The lines from King Lear emphasize the theme of appearance versus reality and highlight Lear's misjudgment when he rejects Cordelia's honesty.
Step-by-step explanation:
The lines from King Lear, "Lear. Let it be so! thy truth then be thy dower!... Let pride, which she calls plainness, marry her," contribute significantly to the play's overarching theme of appearance versus reality. The impact of these lines underscores King Lear's misjudgment based on superficial flattery and the consequences that follow when genuine truth and plainness are rejected. The irony of King Lear's statement is that in casting away Cordelia, who embodies truth and loyalty, Lear is also forsaking the genuine love and honesty which he later realizes are far more valuable than the deceitful flattery offered by his other daughters.