Respuesta :

Answer:

[tex] \sqrt{19} [/tex]

Step-by-step explanation:

Pythagoras

c² = a² + b²

with c being the Hypotenuse (= the side opposite of the 90 degree angle).

=>

10² = 9² + b²

100 = 81 + b²

19 = b²

b = sqrt(19) (≈ 4.36)