Answer
$c=2\sqrt{41}
\\\\
c\approx12.806
$
Work Step by Step
In the given right triangle, $a$ and $b$ are the legs and $c$ is the hypotenuse. Using $a^2+b^2=c^2$ or the Pythagorean Theorem, with $
a=8
$ and $
b=10
,$ then
\begin{array}{l}\require{cancel}
a^2+b^2=c^2
\\\\
8^2+10^2=c^2
\\\\
64+100=c^2
\\\\
164=c^2
\\\\
c=\sqrt{164}
\\\\
c=\sqrt{4\cdot41}
\\\\
c=\sqrt{(2)^2\cdot41}
\\\\
c=2\sqrt{41}
\\\\
c\approx12.806
.\end{array}