Algebra: A Combined Approach (4th Edition)

$10$
According to the Pythagoras Theorem, if $a$ and $b$ are the lengths of the legs of a right triangle, and $c$ is the length of the hypotenuse, then $a^{2}+b^{2}=c^{2}$. Since $a=8$ and $b=6$, we substitute these values in the formula and solve: $c^{2}=a^{2}+b^{2}=8^{2}+6^{2}=64+36=100$ Therefore, $c=\sqrt (100)=10$ Since $c$ represents a length, we assume that $c$ is positive and is equal to $10$.