Question

proofs with parallel lines and transversals
given: lines b and c are parallel
and line a is a transversal.
prove: ∠1 is supplementary to ∠7

1. what is the best reason for

after the given statements
the
next statement and reason is
∠5 ≅ ∠1
because of the
corresponding angles
theorem.
because you need to prove that
∠1 is supplementary to ∠7
so start with what you know
about
∠1 or ∠7
\keep your eye on the goal!\
the number 1 comes
first when counting
5 is my favorite
number
you gotta begin
somewhere!

Explanation:

In a geometric proof, we start with given information and use theorems (like the Corresponding Angles Theorem here) to move towards the goal. Since we need to prove ∠1 is supplementary to ∠7, using the Corresponding Angles Theorem (which relates ∠5 and ∠1 as corresponding angles when lines are parallel) is a logical step based on the proof's objective. The other options (number - related or arbitrary statements) have no geometric basis for this proof.

Answer:

Because you need to prove that ∠1 is supplementary to ∠7 so start with what you know about ∠1 or ∠7 "Keep your eye on the goal!"