Answer :
In the right triangle of sides a, b, and c
[tex]a^2+b^2=c^2[/tex]Since a = 12 and c = 20
Substitute them in the given rule
[tex]\begin{gathered} (12)^2+b^2=(20)^2 \\ 144+b^2=400 \end{gathered}[/tex]Subtract 144 from both sides
[tex]\begin{gathered} 144-144+b^2=400-144 \\ b^2=256 \end{gathered}[/tex]Take a square root for both sides
[tex]\begin{gathered} \sqrt[]{b^2}=\sqrt[]{256} \\ b=16 \end{gathered}[/tex]The answer is b = 16