Answer:
10 in.
Explanation:
The area of a rhombus is the product of the lengths of the diagonals divided by 2.
Let the diagonals be x and y.
area = xy/2
Here you have
area = 40 in.^2
x = 8 in.
We are looking for y, the other diagonal.
xy/2 = area
(8 in.)y/2 = 40 in.^2
(8 in.)y = 80 in.^2
y = 10 in.
Answer: The other diagonal has length 10 in.