Respuesta :

Answer:

7.5

Step-by-step explanation:

This is a right triangle so the length of hypotenuse is related to other two sides

x^2 + 4^2 = (8.5)^2

x^2 + 16 = 72.25

x^2 = 72.25 - 16

x^2 = 56.25

x = 7.5