For the ellipse $9x^2+36y^2=324$ the eccentricity, length of the major and minor axes are respectively

$$\begin{gathered} 9x^2+36y^2=324 \\ \Rightarrow \frac{x^2}{36}+\frac{y^2}{9}=1 \\ \Rightarrow a^2=36,b^2=9 \\ eccentricity =e=\sqrt{1-\frac{b^2}{a^2}}=\sqrt{1-\frac{9}{36}}=\sqrt{\frac{27}{36}}=\frac{\sqrt{3}}{2} \\ length of major axis=2a=2\left(6\right)=12 \\ length of minor axis=2b=2\left(3\right)=6 \end{gathered}$$