In this question, we are given two similar triangles ABC and DEF.
Similar triangles:
The triangles are similar if they have congruent corresponding angles and the corresponding sides of triangles are in proportion.
Therefore, the proportion of all sides should be the same. To proportion (k) can be found using:
k = Side AB / side DE
k = 9/6
or
k = 3/2
Similarly, the 'k' should be the same for side BC and side EF. Therefore,
k = side BC/ side EF
Now, put the values in the equation
Therefore, the value of x would be 4.