I need help asap!!!!!

Answer:
16.7
Step-by-step explanation:
We can use the Pythagorean Theorem [tex]a^{2}[/tex] + [tex]b^{2}[/tex] = [tex]c^{2}[/tex]. So we write the equation below and solve for b.
[tex]9^{2}[/tex] + [tex]b^{2}[/tex] = [tex]19^{2}[/tex]
81 + [tex]b^{2}[/tex] = 361
[tex]b^{2}[/tex] = 280
b = 16.7