Answer: 8
As you can see, ABCD is similar to FECG which means its just a bigger or smaller version of the other. The sides change by a specific amount like times 2 or divided by 2
In this case abcd is 2x bigger thab fecg. You can see this by the side BC being 10 and it is the same side on the other shape being 5 so you know FECG is just ABCD x 1/2
Because of this since we know what FG is (4) on FECG we know y is 2x that side so it is 8.
