# How do you find abs( 3 - 7i )?

$\sqrt{58}$
$| x + i y | = \sqrt{{x}^{2} + {y}^{2}}$
Here, x=3 and $y = - 9$
$\sqrt{{3}^{2} + {\left(- 7\right)}^{2}} = \sqrt{58}$.