Answer:
10.3
Step-by-step explanation:
Pythagorean Theorem:
[tex]a^{2} + b^{2} = c^{2} \\[/tex]
a and b being the sides and c being the hypotenuse.
[tex]3.9^{2} + b^{2} = 11^{2}[/tex]
15.21 + [tex]b^{2}[/tex] = 121
[tex]b^{2}[/tex] = 121 - 15.21
[tex]b^{2}[/tex] = 105.79
b = [tex]\sqrt{105.79}[/tex]
b = 10.3
Hope that helped!!! k
