Answer:

Step-by-step explanation:
The given triangle is a 45-45-90 degree triangle
the common ratio for this 45-45-90 degree triangle is
x : x : 
the side length opposite of 45 degree is x
Given the side length is 8 . so 
we need to find out h that is the hypotenuse
hypotensue is 
we know x is 8, plug in x
h= 