To find the missing side length (a) in the parallelogram, we can use the fact that opposite sides of a parallelogram are equal in length.

Given that side length (d) is 5 and the perimeter (P) is 32, we know that the opposite side length is also 5.

Since a parallelogram has two pairs of equal sides, we can determine the value of (a) by subtracting the sum of the known side lengths from the perimeter and dividing by 2 to find the length of each unknown side:

(5 + 5 + a + a = 32)
(10 + 2a = 32)
(2a = 22)
(a = 11)

Therefore, the missing side length (a) is 11.