[tex]2\sqrt[]{2}[/tex]
1) Considering that this is a right triangle, we can find the missing sides by writing out the Pythagorean Relation.
2) Since there are two congruent legs, we can give those legs the same value.
[tex]\begin{gathered} a^2=b^2+c^2 \\ 16=x^2+x^2 \\ 16=2x^2 \\ 2x^2=16 \\ \frac{2x^2}{2}=\frac{16}{2} \\ x^2=8 \\ x=\pm\sqrt[]{8} \\ x=\pm2\sqrt[]{2}\approx2.82842 \end{gathered}[/tex]
Note that there are no negative lengths, so we can discard the negative result and state the answer as
