Answer
$10
\text{ units}
$
Work Step by Step
Using $|a+bi|=\sqrt{a^2+b^2},$ then the given expression, $
|8-6i|
,$ is equal to
\begin{array}{l}\require{cancel}
\sqrt{8^2+(-6)^2}
\\\\=
\sqrt{64+36}
\\\\=
\sqrt{100}
\\\\=
10
\text{ units}
.\end{array}