Which group of words in the following sentence is an infinitive?
“to learn was eric’s main purpose for going to all those booths.”
a: to learn
b: was eric’s main purpose
c: for going
d: to all the booths

a: to learn

Explanation:

Infinitive is the basic form of a verb, without an inflection binding it to a particular subject or tense. The infinitive is often used with 'to' in front of it.

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