Answer:
x = 10.5
Explanation:
The first thing you have to do is to find out what you multiplied (say) 2 by to get 3.5 and then try it again with another number.
2k = 3.5 Divide by 2
k = 3.5 / 2
k = 1.75
Now try it on another number. What do you multiply 4 by to get 7
4k = 7 Divide by 4
k = 7/4
k = 1.75
So here's what's going on. If you multiply every dimension you are given on the left pentagon (it's not regular) by 1.75, you should get the corresponding number on the right.
To get x you need to multiply 6 by 1.75
x = 6*1.75
x = 10.5