can someone step by step explain the answer please

Answer: z = [tex]\sqrt{10}[/tex]
Step-by-step explanation:
To find z, you must set up a proportion to solve.
To find the altitude of a special right triangle, the formula is:
[tex]\frac{a}{x} =\frac{x}{b}[/tex]
You can use 5 as a and 2 as b to complete the proportion:
[tex]\frac{5}{z} =\frac{z}{2}[/tex]
Next, to solve:
Step 1: Cross-multiply.
[tex]\frac{5}{z} =\frac{z}{2}[/tex]
(5)*(2) = z*z
10 = z²
Step 2: Take square root.
10 = z²
√10 = z
I hope this helps!