Reread lines 20-21. What is the meaning of these lines in terms
of Whitman's extended metaphor?

In "O Captain My Captain" by Whitman, The extended metaphor of the poem compares President Lincoln to a captain steering the "ship of state" which means guiding the union through the civil war.

Explanation:

An extended metaphor means; A metaphor that unfolds across multiple lines or paragraphs of a text, making use of multiple interrelated metaphors in an overarching one. The "captain' of the title however, becomes less essential to the progressive success and unity of the nation as it seemed in the beginning. because at first the "captain" (President Lincoln) is seen as entirely responsible for the safe return of the ship home.

But, the citizens continue to rejoice after their captain has fallen, they did not let the grief of the assassination on the president stop them from continuing their celebration as well as moving on with their lives.

the answer is

r ≈5.641

plug in the area of 100 yards into the equation

100=

divide each side by pi

≈ 31.8309=

take the square root of each side to find r

=r

r ≈5.641

i think the correct answer would be adjustments in life roles.  this causes for one to adjust or change totally his/her career or lifestyle since the present is not beneficial to the life role he is at. for instance, you became a mother you would of course stop going to malls and enjoying life outside. you would be staying at home taking care of your child.