Answer
See image:
.
Work Step by Step
In the xy plane $(z=0)$:
$\displaystyle \frac{x^{2}}{1^{2}}+\frac{y^{2}}{3^{2}}=1\qquad$ ... ellipse
In the xz plane ($y=0)$
$\displaystyle \frac{x^{2}}{1^{2}}+\frac{z^{2}}{3^{2}}=1\qquad$ ... ellipse
In the yz plane $(x=0):$
$ y^{2}+z^{2}=3^{2}\qquad$ ... circle
