plzz help me with this question

Answer:
x = 5
Step-by-step explanation:
We need to find the value of x in this case.
For this, we need to consider that the triangles are similar. Now, we can find it as follows :
[tex]\dfrac{12}{3}=\dfrac{20}{x}\\\\x=\dfrac{20\times 3}{12}\\\\x=5[/tex]
So, the value of x is equal to 5.