Which narrative technique does the author include in this expert and how does it support the authors purpose

Common techniques relevant to style, or the language chosen to tell a story, include metaphors, similes, personification, imagery, hyperbole, and alliteration.

the answer is c or the third one.

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