The following shapes are similar find the missing side

We will create a proportional relationship to find x.
[tex]\frac{12}{3} = \frac{20}{x}\\\\12x = 60\\\\x = 5[/tex]
The missing side is D. x = 5.
Answer:
I don't know the exact answer but I that x=5
Step-by-step explanation:
12/3=20/x
12x=20*3
12x=60
x=60/12
x=5