given that the triangles below are similar.find the scale factor

The triangles are similar, then scale factor is equal to ratio of corresponding sides of two triangle.
[tex]\begin{gathered} x=\frac{24}{30} \\ =\frac{4}{5} \\ =\text{0}.8 \end{gathered}[/tex]Or
[tex]\begin{gathered} x=\frac{32}{40} \\ =\frac{4}{5} \\ =0.8 \end{gathered}[/tex]Thus, scale factor for the triangles is 0.8.