Question

These two rectangles are similar which is a correct proportion for corresponding sides

Answer 1

to make the proportion we make the ratio of the similar sides

For example

4/8 = 12/x

or we can write it as 4/12 = 8/x

or 12/x = 4/8

So last option is correct

Answer 2

It would be 12/x=4/8 i just took it