Answer:
6
Step-by-step explanation:
I am not completely sure.
3x
if x=4 then it would be 12
if x=6 then it would be 18
if x=9 then it would be 27
if x=10 then it would be 30
the side is shorter than 19 but definitely longer than 6. To me, it looks like a little more than double, more of triple and 6 times 3 is 18.
