If p and q are parallel lines intersected by a transversal line, then the angles ∠1 and ∠3 are corresponding angles (the lines make an F-shape.). Corresponding angles are congruent so that:
[tex]\begin{gathered} \angle1=\angle3 \\ 6x=120 \end{gathered}[/tex]
Divide both sides by 6 to determine the value of x
[tex]\begin{gathered} \frac{6x}{6}=\frac{120}{6} \\ x=20 \end{gathered}[/tex]
For x=20 lines p and q can be considered to be parallel
