Answer: z =

Explanation:
To find z, you must set up a proportion to solve.
To find the altitude of a special right triangle, the formula is:

You can use 5 as a and 2 as b to complete the proportion:

Next, to solve:
Step 1: Cross-multiply.

(5)*(2) = z*z
10 = z²
Step 2: Take square root.
10 = z²
√10 = z
I hope this helps!