Locate the points for which $\; 3 < |z| < 4$

Question

$(a)\;x^{2}+y^{2}=9 \;and\;x^{2}+y^{2} =16\qquad(b)\;x^{2}+y^{2}=4 \;and\;x^{2}+y^{2} =9\qquad(c)\;x^{2}+y^{2}=9 \;and\;x^{2}+y^{2} =3\qquad(d)\;x^{2}+y^{2}=0 \;and\;x^{2}+y^{2} =16$