Given:
Triangle ABC and triangle DEF are similar triangles.
To find:
The proportion that can be used to find the length of segment DE.
Solution:
We know that the corresponding sides of similar triangles are proportional.
Triangle ABC and triangle DEF are similar triangles. So, their corresponding sides must be proportional.
[tex]\dfrac{AB}{DE}=\dfrac{BC}{EF}=\dfrac{AC}{DF}[/tex]
[tex]\dfrac{AB}{DE}=\dfrac{BC}{EF}[/tex]
[tex]\dfrac{4}{DE}=\dfrac{3}{9}[/tex]
[tex]\dfrac{4}{3}=\dfrac{DE}{9}[/tex]
Therefore, the correct option is A.
