We are given a triangle crossed by two parallel lines. The lines are parallel since their corresponding angles are the same. Therefore, from Thale's theorem we have the following relationship:
[tex]\frac{14}{6}=\frac{x}{9}[/tex]Now we solve for "x" by multiplying by 9 on both sides of the equation:
[tex]\frac{14}{6}\times9=x[/tex]Solving the operations we get:
[tex]21=x[/tex]Therefore, x = 21
