# How do you find abs( 2 + 8i )?

$\left\mid 2 + 8 i \right\mid = 2 \sqrt{17}$
In general $\left\mid a + b i \right\mid = \sqrt{{a}^{2} + {b}^{2}}$
$\textcolor{w h i t e}{\text{XXX}} \left\mid 2 + 8 i \right\mid = \sqrt{{2}^{2} + {8}^{2}} = \sqrt{68} = 2 \sqrt{17}$