Help me please. I don’t understand at all. I’m stressing. Like what?!?!?!

Answer:
z = [tex]\sqrt{117}[/tex]
Step-by-step explanation:
find 'y' first by using the altitude rule:
y/4 = 9/y
cross-multiply:
y² = 4(9)
y² = 36
y = [tex]\sqrt{36}[/tex] = 6
Find 'z' by using the Pythagorean Theorem with legs equal to 6 and 9
6² + 9² = z²
36 + 81 = z²
117 = z²
z = [tex]\sqrt{117}[/tex]