# How do you simplify abs(-3.6i )?

$\left\mid - 3.6 i \right\mid = 3.6$
Since $\left(- 3.6 i\right)$ has no Real term we are looking at the distance from $\left(0 , 0 i\right)$ along the Imaginary Axis to $\left(0 , - 3.6 i\right)$
This distance is clearly $3.6$ units.