Respuesta :

For the given similar polygons, the value of x equal to 30.

Similar Polygons

Two polygons are classified as similar when their angles are congruent and their sides are proportional.

If the polygons of this exercise are similar. You can write:

                                   [tex]\frac{LK}{QR}=\frac{JK}{PR}=\frac{JL}{PQ}[/tex]

Then,

                                    [tex]\frac{LK}{QR}=\frac{JK}{PR}=\frac{JL}{PQ}\\ \\ \frac{18}{12}=\frac{x}{20}=\frac{21}{14}[/tex]

It is possible to note that the scale factor is  [tex]\frac{3}{2}[/tex].  See it.

                                         [tex]\frac{18:6}{12:6}=\frac{3}{2} \\ \\ \frac{21:7}{14:7}=\frac{3}{2}[/tex]

Therefore, you can find x from:

                                      [tex]\frac{18}{12}=\frac{x}{20}\\ \\ 12x=18*20\\ \\ 12x=360\\ \\ x=\frac{360}{12} =30[/tex]

Read more about the similar polygons here:

https://brainly.com/question/1442292