Answer
\begin{array}{c|ll}& \textbf{Statement} & \textbf{Reasons}
\\\hline1 & a\parallel b & \text{Given}
\\2 & \angle1\cong\angle5 & \text{Corresponding Angles Theorem}
\\3 & \angle5\cong\angle7 & \text{Vertical Angles Theorem}
\\4 & \angle1\cong\angle7 & \text{Transitive Property of Congruency}
\end{array}
Work Step by Step
Use known theorems and properties of congruence to make the proof.
