The absolute value of a complex number $z=a+b i:|z|=\sqrt{a^{2}+b^{2}}$
The absolute value of a complex number $z$, denoted
$|z|,$ represents the distance between the origin and the point $(a, b)$ in the complex plane. Use the formula to find $|z|$ for the complex numbers given (also see Section $1.4, \text { Exercise } 69):(\mathrm{a}) 3+4 i$
(b) $-5+12 i,$ and $(\mathrm{c}) 1+\sqrt{3} i$