Hey there! I'm happy to help!
First, let's find the length of GA. We can just subtract all of the other sides from the perimeter to find this.
172-56-56-35=25
We see that E'M' is 14 and EM is 35.
35/14=2.5
This means that all of the sides on the big pinball machine are 2.5 times bigger than those of the smaller one.
So, we take the length of GA and then divide it by 2.5 to see how big G'A' is.
25/2.5=10
Therefore, the length of G'A' is 10 inches.
I hope that this helps! Have a wonderful day! :D