Question

Find the missing side

Answer 1

Hi there!
The question here is basically asking us to use ratios to find the length of the missing side. To do this, we must first construct a ratio. The best one would be - 
$\frac{84}{12} = \frac{56}{x}$
Now, just cross multiply and solve for x.
$\frac{84}{12} = \frac{56}{x}$
$84x = 672$
$x = 8$
Therefore, the length of the missing side would be 8. Hope this helped!

Answer 2

I believe it's given that the two triangles are similar

12/84 = x/56

x = 56*12/84 = 8