Answer:
See Below.
Step-by-step explanation:
We are given that ∠1 and ∠7 are supplementary.
And we would like to prove that a is parallel to b.
Statements: Reasons:
[tex]\textbf{\textsf{1. $\angle 1$ and $\angle 7$ are supplementary}}[/tex] Given
[tex]\textsf{2. $m\angle3$ + $m\angle 7$ $= 180$}[/tex] Supplementary Angles
[tex]\textsf{3. $\angle3$ and $\angle7$ are supplementary}[/tex] Definition of Supplementary
[tex]\textsf{4. }\bf{\angle 1 \cong \angle3}[/tex] Congruent Supplements Theorem
[tex]\textsf{5. }a\parallel b[/tex] Corresponding Angles Converse
And we are done!
