Answer:
38cm
Step-by-step explanation:
set 3x-5 and 19-x equal to eachother, since, given as its an isoscles triangle, they should be equal. After you work out the equation, you're left with x=6. So now you plug that it.
3(6)-5=13
19-(6)=13
2(6)=12
Now you add them all together, so the perimeter is 38 cm.
