Assume that the first side of the kite is x and that the second side is y.
The perimeter of the kite is calculated using the following rule:
perimeter = 2(x+y)
We are given that:
perimeter = 38 in
one of the sides (let it be x) = 8 in
Substitute with the givens in the above equation to get the other side (y) as follows:
38 = 2(8+y)
19 = 8+y
y = 19-8 = 11 in