Sketch on a single Argand diagram the loci given by
(a) \(\quad | z | = | z - 8 |\),
(b) \(\quad \arg ( z + 2 \mathrm { i } ) = \frac { 1 } { 4 } \pi\).
Indicate by shading the region of the Argand diagram for which
$$| z | \leqslant | z - 8 | \quad \text { and } \quad 0 \leqslant \arg ( z + 2 i ) \leqslant \frac { 1 } { 4 } \pi$$