Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$c=2\sqrt{41} \\\\ c\approx12.806$
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}